JP2012171825A - Lithium-free silicate-based compound, method for producing the same, positive electrode for lithium ion secondary battery, and the lithium ion secondary battery - Google Patents
Lithium-free silicate-based compound, method for producing the same, positive electrode for lithium ion secondary battery, and the lithium ion secondary battery Download PDFInfo
- Publication number
- JP2012171825A JP2012171825A JP2011034508A JP2011034508A JP2012171825A JP 2012171825 A JP2012171825 A JP 2012171825A JP 2011034508 A JP2011034508 A JP 2011034508A JP 2011034508 A JP2011034508 A JP 2011034508A JP 2012171825 A JP2012171825 A JP 2012171825A
- Authority
- JP
- Japan
- Prior art keywords
- lithium
- silicate compound
- free silicate
- secondary battery
- ion secondary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 21
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 title abstract description 8
- 150000001875 compounds Chemical class 0.000 title description 10
- -1 alkali metal salts Chemical class 0.000 claims abstract description 102
- 229910052751 metal Inorganic materials 0.000 claims abstract description 52
- 239000002184 metal Substances 0.000 claims abstract description 50
- 150000003839 salts Chemical class 0.000 claims abstract description 29
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000000126 substance Substances 0.000 claims abstract description 26
- 239000007774 positive electrode material Substances 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims abstract description 19
- 230000001603 reducing effect Effects 0.000 claims abstract description 18
- 229910004283 SiO 4 Inorganic materials 0.000 claims abstract description 17
- 229910052912 lithium silicate Inorganic materials 0.000 claims abstract description 16
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 14
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 13
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims description 31
- 229910052744 lithium Inorganic materials 0.000 claims description 24
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 22
- 229910052742 iron Inorganic materials 0.000 claims description 17
- 229910052748 manganese Inorganic materials 0.000 claims description 15
- 229910052759 nickel Inorganic materials 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 13
- 229910052749 magnesium Inorganic materials 0.000 claims description 8
- 238000002441 X-ray diffraction Methods 0.000 claims description 7
- 229910052791 calcium Inorganic materials 0.000 claims description 7
- 229910052720 vanadium Inorganic materials 0.000 claims description 7
- 229910052725 zinc Inorganic materials 0.000 claims description 7
- 239000000843 powder Substances 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- 239000000470 constituent Substances 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 27
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 26
- 239000011777 magnesium Substances 0.000 description 17
- 238000006243 chemical reaction Methods 0.000 description 16
- 229910052799 carbon Inorganic materials 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 12
- 239000002994 raw material Substances 0.000 description 12
- 239000006230 acetylene black Substances 0.000 description 9
- 238000002156 mixing Methods 0.000 description 9
- PAZHGORSDKKUPI-UHFFFAOYSA-N lithium metasilicate Chemical class [Li+].[Li+].[O-][Si]([O-])=O PAZHGORSDKKUPI-UHFFFAOYSA-N 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 239000002245 particle Substances 0.000 description 6
- 239000011575 calcium Substances 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 239000011812 mixed powder Substances 0.000 description 5
- 238000003786 synthesis reaction Methods 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 238000001027 hydrothermal synthesis Methods 0.000 description 4
- 239000003273 ketjen black Substances 0.000 description 4
- 239000004570 mortar (masonry) Substances 0.000 description 4
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 4
- 239000004810 polytetrafluoroethylene Substances 0.000 description 4
- 150000004760 silicates Chemical class 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000000498 ball milling Methods 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 239000002134 carbon nanofiber Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 238000003746 solid phase reaction Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000002482 conductive additive Substances 0.000 description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910003002 lithium salt Inorganic materials 0.000 description 2
- 159000000002 lithium salts Chemical class 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 239000001103 potassium chloride Substances 0.000 description 2
- 235000011164 potassium chloride Nutrition 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910000288 alkali metal carbonate Inorganic materials 0.000 description 1
- 150000008041 alkali metal carbonates Chemical class 0.000 description 1
- 229910001514 alkali metal chloride Inorganic materials 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 229910001963 alkali metal nitrate Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical class [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- WDHWFGNRFMPTQS-UHFFFAOYSA-N cobalt tin Chemical compound [Co].[Sn] WDHWFGNRFMPTQS-UHFFFAOYSA-N 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- VEPSWGHMGZQCIN-UHFFFAOYSA-H ferric oxalate Chemical compound [Fe+3].[Fe+3].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O VEPSWGHMGZQCIN-UHFFFAOYSA-H 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 description 1
- 229910001486 lithium perchlorate Inorganic materials 0.000 description 1
- 229910001629 magnesium chloride Inorganic materials 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000009931 pascalization Methods 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910001428 transition metal ion Inorganic materials 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Silicates, Zeolites, And Molecular Sieves (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
【課題】リチウムイオン二次電池用正極材料として有用なリチウムフリーシリケート系材料と、そのリチウムフリーシリケート系材料を比較的簡単な手段によって製造できる方法を提供する。
【解決手段】アルカリ金属塩から選ばれた少なくとも一種を含む溶融塩中で、二酸化炭素および還元性ガスを含む混合ガス雰囲気下において、珪酸リチウム化合物と、第一金属元素含有物質と、第二金属元素含有物質と、を350℃以上600℃以下で反応させることで、（Fe1-xMgx）2SiO4などと表されるリチウムフリーシリケート系化合物を得る。
【選択図】図5A lithium-free silicate material useful as a positive electrode material for a lithium-ion secondary battery and a method for producing the lithium-free silicate material by a relatively simple means are provided.
In a molten salt containing at least one selected from alkali metal salts, in a mixed gas atmosphere containing carbon dioxide and a reducing gas, a lithium silicate compound, a first metal element-containing substance, and a second metal By reacting the element-containing substance with a temperature of 350 ° C. or higher and 600 ° C. or lower, a lithium-free silicate compound represented by (Fe 1-x Mg x ) 2 SiO 4 or the like is obtained.
[Selection] Figure 5
Description
本発明は、主としてリチウムイオン二次電池の正極活物質として有用なリチウムフリーシリケート系化合物とその製造方法、及びこの化合物を用いたリチウムイオン二次電池用正極とリチウムイオン二次電池に関する。 The present invention mainly relates to a lithium-free silicate compound useful as a positive electrode active material of a lithium ion secondary battery, a method for producing the same, and a positive electrode for a lithium ion secondary battery and a lithium ion secondary battery using the compound.
リチウムイオン二次電池は、小型でエネルギー密度が高く、ポータブル電子機器の電源として広く用いられている。近年、その正極活物質として、Li2FeSiO4（理論容量331.3mAh/g）、Li2MnSiO4（理論容量333.2mAh/g）等のリチウムシリケート系化合物が注目されている。リチウムシリケート系化合物は、安価で、資源量の豊富な構成金属元素のみからなるために環境負荷が低く、高いリチウムイオンの理論充放電容量を有し、かつ高温時に酸素を放出しにくい材料であることから、次世代リチウムイオン二次電池正極材料として注目されている。 Lithium ion secondary batteries are small and have high energy density, and are widely used as power sources for portable electronic devices. In recent years, lithium silicate compounds such as Li 2 FeSiO 4 (theoretical capacity 331.3 mAh / g) and Li 2 MnSiO 4 (theoretical capacity 333.2 mAh / g) have attracted attention as positive electrode active materials. Lithium silicate-based compounds are low-cost materials that are composed of only abundant constituent metal elements, have low environmental impact, have high lithium ion theoretical charge / discharge capacity, and are difficult to release oxygen at high temperatures. Therefore, it is attracting attention as a positive electrode material for next-generation lithium ion secondary batteries.
リチウムシリケート系化合物の合成法としては、水熱合成法と固相反応法が知られている。これらの方法のうち、水熱合成法によれば、粒径1〜10nm程度の微粒子を得ることが可能である。しかし、水熱合成法により得られたシリケート系化合物は、ドープ元素が固溶し難い、不純物相が混在し易い、また、発現する電池特性もさほど良好ではない、という問題がある。これは、合成温度が低く反応に長時間を要する上に、リチウム原料を過剰に仕込まないとリチウムシリケート系化合物の合成が困難であるためと考えられる。また、このような方法に用いる水熱反応装置は、高圧処理が必要なため特殊な設備が必要であり、量産化には不利である。 Hydrothermal synthesis methods and solid phase reaction methods are known as methods for synthesizing lithium silicate compounds. Among these methods, the hydrothermal synthesis method can obtain fine particles having a particle size of about 1 to 10 nm. However, the silicate compound obtained by the hydrothermal synthesis method has a problem that the dope element is hardly dissolved, the impurity phase is likely to be mixed, and the battery characteristics to be expressed are not so good. This is presumably because the synthesis temperature is low and the reaction takes a long time, and it is difficult to synthesize the lithium silicate compound unless the lithium raw material is charged excessively. Moreover, since the hydrothermal reaction apparatus used for such a method requires high pressure processing, special equipment is required, which is disadvantageous for mass production.
一方、固相反応法では、650℃以上という高温で長時間反応させることが必要であり、ドープ元素を固溶させることは可能であるが、結晶粒が10μｍ以上と大きくなり、イオンの拡散が遅いという問題がある。高温で反応させるため、冷却過程で固溶しきれないドープ元素が析出して不純物が生成し、抵抗が高くなるという問題もある。さらに、高温まで加熱するために、リチウム欠損や酸素欠損のリチウムシリケート系化合物ができ、容量の増加やサイクル特性の向上が難しいという問題もある（下記特許文献1〜4等参考）。
On the other hand, in the solid phase reaction method, it is necessary to react at a high temperature of 650 ° C. or higher for a long time, and it is possible to dissolve the dope element, but the crystal grains become as large as 10 μm or more, and the diffusion of ions is increased. There is a problem of being slow. Since the reaction is performed at a high temperature, a doping element that cannot be completely dissolved in the cooling process is precipitated to generate impurities, resulting in a high resistance. Further, since the lithium silicate compound having lithium deficiency or oxygen deficiency is formed because of heating to a high temperature, there is a problem that it is difficult to increase capacity and improve cycle characteristics (see
たとえば、上記のような方法により合成されるリチウムシリケート系材料のうちで、現在報告されている最も高い充放電特性を示す材料は、Li2FeSiO4であり、160mAh/g程度の容量を示す。しかし、Li2FeSiO4について60℃で評価すると150mAh/g程度の容量が見られるものの、室温において同様な条件で評価すると容量が大幅に低下して60mAh/g程度の容量しか見られない、という問題がある。 For example, among the lithium silicate materials synthesized by the method as described above, the currently reported material having the highest charge / discharge characteristics is Li 2 FeSiO 4, which has a capacity of about 160 mAh / g. However, when Li 2 FeSiO 4 is evaluated at 60 ° C, a capacity of about 150 mAh / g is seen, but when evaluated under the same conditions at room temperature, the capacity is greatly reduced and only a capacity of about 60 mAh / g is seen. There's a problem.
本発明者等は、サイクル特性、容量等が改善された、優れた性能を有する材料を比較的簡単な手段によって製造できる方法を見出した。特許文献5には、実施例1として、炭酸リチウムを含む炭酸塩溶融塩中で、還元雰囲気下において、珪酸リチウム化合物とシュウ酸鉄とを550℃で反応させることで合成した、鉄含有リチウムシリケート系化合物（Li2FeSiO4）が記載されている。
The inventors of the present invention have found a method by which a material having excellent performance with improved cycle characteristics and capacity can be produced by relatively simple means.
特許文献5に記載の方法によれば、従来の固相反応法よりもサイクル特性が良好で高容量のリチウムシリケート系化合物を合成することができた。しかし、鉄含有リチウムシリケート系化合物（Li2FeSiO4）などは、リチウムを含んでいるためにコストが高いという問題があった。そこで本願発明者らは、リチウムを含まないシリケート正極活物質の探索を行い、特許文献5に記載の方法で製造することで得られたいくつかのシリケート系化合物がリチウムイオン電池の正極活物質として有用であることを見出した。
According to the method described in
すなわち本発明は、リチウムイオン二次電池用正極材料として有用なリチウムフリーシリケート系材料と、そのリチウムフリーシリケート系材料を比較的簡単な手段によって製造できる方法を提供することを目的とする。 That is, an object of the present invention is to provide a lithium-free silicate material useful as a positive electrode material for a lithium ion secondary battery and a method capable of producing the lithium-free silicate material by a relatively simple means.
すなわち、本発明のリチウムフリーシリケート系化合物の特徴は、組成式：（M1-xM'x）2SiO4（式中、Mは、Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の元素であり、M'は、Mg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の元素であり、0≦x≦0.5である）で表されることにある。 That is, the characteristics of the lithium-free silicate compound of the present invention are characterized by the composition formula: (M 1-x M ′ x ) 2 SiO 4 (wherein M is selected from the group consisting of Fe, Co, Ni and Mn) And at least one element, and M ′ is at least one element selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V, and 0 ≦ x ≦ 0.5) It is to be done.
また上記リチウムフリーシリケート系化合物を製造できる本発明の製造方法の特徴は、アルカリ金属塩から選ばれた少なくとも一種を含む溶融塩中で、二酸化炭素および還元性ガスを含む混合ガス雰囲気下において、
Li2SiO3で表される珪酸リチウム化合物と、
Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の元素を含む第一金属元素含有物質と、
Mg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の元素を含む第二金属元素含有物質と、を350℃以上600℃以下で反応させることにある。
In addition, the feature of the production method of the present invention that can produce the lithium-free silicate-based compound is a molten salt containing at least one selected from alkali metal salts in a mixed gas atmosphere containing carbon dioxide and a reducing gas.
A lithium silicate compound represented by Li 2 SiO 3 ;
A first metal element-containing material containing at least one element selected from the group consisting of Fe, Co, Ni and Mn;
The object is to react a second metal element-containing substance containing at least one element selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V at 350 ° C. or higher and 600 ° C. or lower.
本発明のリチウムフリーシリケート系化合物を正極活物質として用いたリチウムイオン二次電池では、放電時に負極から供給されたリチウムが（M1-xM'x）2SiO4の結晶格子間に挿入される。そして充電時には、正極からのリチウムの離脱とともにM'の析出が生じる。このとき、M'が析出することによって正極には空隙が生じ、次の放電時にリチウムが挿入されるサイトが増えるため、高い容量が発現される。またM'の析出によって電解液の分解で生じるフッ酸に対する正極の耐性が向上し、サイクル特性が向上するという効果も発現される。 In the lithium ion secondary battery using the lithium-free silicate compound of the present invention as the positive electrode active material, lithium supplied from the negative electrode during discharge is inserted between the crystal lattices of (M 1-x M ′ x ) 2 SiO 4. The At the time of charging, M ′ precipitates with the release of lithium from the positive electrode. At this time, since M ′ is deposited, voids are generated in the positive electrode, and the number of sites into which lithium is inserted during the next discharge increases, so that a high capacity is exhibited. In addition, the effect of improving the cycle characteristics by improving the resistance of the positive electrode to hydrofluoric acid generated by the decomposition of the electrolytic solution due to the deposition of M ′ is also exhibited.
また本発明のリチウムフリーシリケート系化合物は、格子間にケイ酸イオンが存在するため結晶構造が安定化し、正極材料として用いた場合に二次電池のサイクル特性を安定化させる効果があると推測される。さらに、格子間に陽イオンであるケイ酸イオンが存在することで、陰イオンであるリチウムイオンとの距離が近接するため、静電作用によりリチウムイオンが抜けやすくなり、充電電圧を下げる効果も期待される。その結果、高電圧まで充電しなくても、高い充電容量を得ることが可能となる。また、充電電圧を下げることで電解液の分解による不可逆容量を低減でき、高い充放電効率を有する材料となりえる。 The lithium-free silicate compound of the present invention is presumed to have an effect of stabilizing the cycle characteristics of the secondary battery when used as a positive electrode material because the silicate ions exist between the lattices and the crystal structure is stabilized. The In addition, the presence of silicate ions, which are cations, between the lattices makes the distance from the lithium ions, which are anions, close to each other. Is done. As a result, a high charge capacity can be obtained without charging to a high voltage. Moreover, the irreversible capacity | capacitance by decomposition | disassembly of electrolyte solution can be reduced by reducing a charging voltage, and it can become a material which has high charging / discharging efficiency.
そして本発明のリチウムフリーシリケート系化合物は、リチウムを含まないので安価となる。したがって本発明のリチウムフリーシリケート系化合物を正極活物質として用いたリチウムイオン二次電池も安価となる。 The lithium-free silicate compound of the present invention is inexpensive because it does not contain lithium. Therefore, a lithium ion secondary battery using the lithium-free silicate compound of the present invention as the positive electrode active material is also inexpensive.
そして本発明のリチウムフリーシリケート系化合物の製造方法によれば、安価で、資源量が多くかつ環境負荷が低い原料を用いて、リチウムフリーシリケート系化合物が容易に得られる。また、本発明の製造方法により得られるリチウムフリーシリケート系化合物は、リチウムイオン二次電池の正極活物質として用いた場合に、優れた電池特性を示す。 According to the method for producing a lithium-free silicate compound of the present invention, a lithium-free silicate compound can be easily obtained using a raw material that is inexpensive, has a large amount of resources, and has a low environmental load. In addition, the lithium-free silicate compound obtained by the production method of the present invention exhibits excellent battery characteristics when used as a positive electrode active material of a lithium ion secondary battery.
本発明のリチウムフリーシリケート系化合物は、組成式：（M1-xM'x）2SiO4（式中、Mは、Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の元素であり、M'は、Mg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の元素であり、0≦x≦0.5である）で表される。 The lithium-free silicate compound of the present invention has a composition formula: (M 1-x M ′ x ) 2 SiO 4 (wherein M is at least one element selected from the group consisting of Fe, Co, Ni and Mn) M ′ is at least one element selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V, and 0 ≦ x ≦ 0.5.
金属MがFeであり、金属M'がMgの場合には、本発明のリチウムフリーシリケート系化合物は（Fe1-xMgx）2SiO4の組成式で表される。このリチウムフリーシリケート系化合物は、CuＫα線を用いるＸ線回折測定において、回折角（2θ）が25.3°付近に現れる回折ピークと22.7°付近に現れる回折ピークとを有し、このことによって同定することが可能である。一方、格子定数の組成依存性は線形関係に従う。またｘが0、0.5、1の場合のa軸、b軸、c軸のそれぞれについて格子定数が報告されている。したがってa軸、b軸、c軸についてそれぞれ近似直線を算出し、実測された格子定数からｘの値を算出することができる。 When the metal M is Fe and the metal M ′ is Mg, the lithium-free silicate compound of the present invention is represented by a composition formula of (Fe 1-x Mg x ) 2 SiO 4 . This lithium-free silicate compound has a diffraction peak with a diffraction angle (2θ) around 25.3 ° and a diffraction peak around 22.7 ° in the X-ray diffraction measurement using CuKα rays. Is possible. On the other hand, the composition dependence of the lattice constant follows a linear relationship. Lattice constants are reported for each of the a-axis, b-axis, and c-axis when x is 0, 0.5, and 1. Accordingly, approximate lines can be calculated for the a-axis, b-axis, and c-axis, respectively, and the value of x can be calculated from the actually measured lattice constant.
以下、本発明の製造方法を説明する。なお、特に断らない限り、本明細書でいう「ｐ〜ｑ」は下限ｐおよび上限ｑを含む。
＜溶融塩の組成＞
本発明のリチウムフリーシリケート系化合物の製造方法では、アルカリ金属塩から選ばれた少なくとも一種を含む溶融塩中において、リチウムフリーシリケート系化合物の合成反応を行う。アルカリ金属塩としては、カリウム塩、ナトリウム塩、ルビシウム塩およびセシウム塩からなる群から選ばれる少なくとも一種が挙げられる。また、アルカリ金属塩の種類に特に限定はないが、アルカリ金属塩化物、アルカリ金属炭酸塩、アルカリ金属硝酸塩などから選択して用いることができる。場合によっては、アルカリ金属水酸化物を用いることもできる。
Hereinafter, the production method of the present invention will be described. Unless otherwise specified, “p to q” in this specification includes the lower limit p and the upper limit q.
<Composition of molten salt>
In the method for producing a lithium-free silicate compound of the present invention, a lithium-free silicate compound is synthesized in a molten salt containing at least one selected from alkali metal salts. Examples of the alkali metal salt include at least one selected from the group consisting of potassium salt, sodium salt, rubium salt, and cesium salt. Further, the kind of alkali metal salt is not particularly limited, but can be selected from alkali metal chloride, alkali metal carbonate, alkali metal nitrate, and the like. In some cases, an alkali metal hydroxide can also be used.
溶融塩は、溶融温度が600℃以下となるように上記のアルカリ金属塩から選択し、アルカリ金属塩を混合して用いるのであれば混合物の溶融温度が600℃以下となるように混合比を調節して混合溶融塩を得ればよい。混合比は、塩の種類に応じて異なるため、一概に規定することは困難である。
＜原料化合物＞
本発明では、Li2SiO3で表される珪酸リチウム化合物と、第一金属元素含有物質と、第二金属元素含有物質とを原料化合物とする。第一金属元素含有物質としては、Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の第一金属元素とを含む物質を用いる。また第二金属元素含有物質としては、Mg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の第二金属元素を含む物質を用いる。
The molten salt is selected from the above alkali metal salts so that the melting temperature is 600 ° C. or less, and if the alkali metal salts are mixed and used, the mixing ratio is adjusted so that the melting temperature of the mixture is 600 ° C. Thus, a mixed molten salt may be obtained. Since the mixing ratio varies depending on the type of salt, it is difficult to define it unconditionally.
<Raw compound>
In the present invention, a lithium silicate compound represented by Li 2 SiO 3 , a first metal element-containing material, and a second metal element-containing material are used as raw material compounds. As the first metal element-containing substance, a substance containing at least one first metal element selected from the group consisting of Fe, Co, Ni, and Mn is used. As the second metal element-containing substance, a substance containing at least one second metal element selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V is used.
Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の第一金属元素を含む物質、あるいはMg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の第二金属元素を含む物質としては、これらから選択された金属、これらから選択された金属元素の塩、これらから選択された金属元素を含む水溶液をアルカリ性にして形成される沈殿物などが例示される。第一金属元素含有物質は金属粉末であることが好ましく、第二金属元素含有物質は塩化物であることが好ましい。 A substance containing at least one first metal element selected from the group consisting of Fe, Co, Ni and Mn, or at least one selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V Examples of the substance containing the second metal element include a metal selected from these, a salt of the metal element selected from these, and a precipitate formed by making the aqueous solution containing the metal element selected from these alkaline. Is done. The first metal element-containing substance is preferably a metal powder, and the second metal element-containing substance is preferably a chloride.
第一金属元素含有物質と第二金属元素含有物質との混合量は、第一金属元素(M)がモル量(１−ｘ）であり、第二金属元素(M')がモル量(ｘ)となるようにする。ｘの範囲は、0≦ｘ≦0.5である。ｘが0.5を超えると、置換されるリチウムイオンの量が過剰となるため好ましくない。 The mixing amount of the first metal element-containing substance and the second metal element-containing substance is such that the first metal element (M) is a molar amount (1-x) and the second metal element (M ′) is a molar amount (x ). The range of x is 0 ≦ x ≦ 0.5. When x exceeds 0.5, the amount of lithium ions to be substituted becomes excessive, which is not preferable.
Li2SiO3で表される珪酸リチウム化合物と、第一金属元素及び第二金属元素との混合割合については、通常、珪酸リチウム化合物１モルに対して、第一金属元素と第二金属元素との合計量が0.9〜1.2モルとなる量とすることが好ましく、0.95〜1.1モルとなる量とすることがより好ましい。
＜リチウムフリーシリケート系化合物の製造方法＞
本発明のリチウムフリーシリケート系化合物の製造方法では、上記の溶融塩中で、二酸化炭素および還元性ガスを含む混合ガス雰囲気下において、上記の原料化合物を350〜600℃で反応させることが必要である。
About the mixing ratio of the lithium silicate compound represented by Li 2 SiO 3 and the first metal element and the second metal element, the first metal element and the second metal element are usually added to 1 mol of the lithium silicate compound. The total amount is preferably 0.9 to 1.2 mol, and more preferably 0.95 to 1.1 mol.
<Method for producing lithium-free silicate compound>
In the method for producing a lithium-free silicate compound of the present invention, it is necessary to react the raw material compound at 350 to 600 ° C. in the molten salt in a mixed gas atmosphere containing carbon dioxide and a reducing gas. is there.
具体的な反応方法については特に限定的ではないが、通常は、上記したアルカリ金属塩から選ばれた少なくとも一種を含む溶融塩原料、珪酸リチウム化合物、第一金属元素含有物質、第二金属元素含有物質を混合し、ボールミル等を用いて均一に混合した後、溶融塩原料の融点以上に加熱して溶融塩原料を溶融させればよい。これにより、溶融塩中において、リチウム、珪素、第一金属元素、第二金属元素の反応が進行して、目的とするリチウムフリーシリケート系化合物を得ることができる。 The specific reaction method is not particularly limited, but usually a molten salt raw material containing at least one selected from the alkali metal salts described above, a lithium silicate compound, a first metal element-containing material, a second metal element-containing After the substances are mixed and uniformly mixed using a ball mill or the like, the molten salt raw material may be melted by heating to a temperature higher than the melting point of the molten salt raw material. Thereby, reaction of lithium, silicon, a 1st metal element, and a 2nd metal element advances in molten salt, and the target lithium free silicate type compound can be obtained.
この際、溶融塩原料と、珪酸リチウム化合物と、第一金属元素含有物質と、第二金属元素含有物質と、の混合割合については特に限定的ではなく、溶融塩中において、原料を均一に分散できる量であればよい。たとえば、珪酸リチウム化合物と第一金属元素含有物質及び第二金属元素含有物質の合計量100質量部に対して、溶融塩原料の合計量が20〜300質量部の範囲となる量であることが好ましく、50〜200質量部さらには60〜120質量部の範囲となる量であることがより好ましい。 At this time, the mixing ratio of the molten salt raw material, the lithium silicate compound, the first metal element-containing substance, and the second metal element-containing substance is not particularly limited, and the raw material is uniformly dispersed in the molten salt. Any amount can be used. For example, the total amount of the molten salt raw material is in the range of 20 to 300 parts by mass with respect to 100 parts by mass of the total amount of the lithium silicate compound, the first metal element-containing substance and the second metal element-containing substance. The amount is preferably 50 to 200 parts by mass, and more preferably 60 to 120 parts by mass.
溶融塩中における反応温度は、350〜600℃さらには400〜560℃であればよい。350℃未満では、溶融塩中にO2-が放出されにくく、リチウムフリーシリケート系化合物が合成されるまでに長時間を要するため、実用的ではない。また、600℃を超えると、得られるリチウムフリーシリケート系化合物の粒子が粗大化し易くなるため好ましくない。 The reaction temperature in the molten salt may be 350 to 600 ° C, further 400 to 560 ° C. Below 350 ° C., it is not practical because O 2− is not easily released into the molten salt, and it takes a long time to synthesize a lithium-free silicate compound. On the other hand, when the temperature exceeds 600 ° C., the resulting lithium-free silicate compound particles are likely to be coarsened, which is not preferable.
上記した反応は、反応時において、第一金属元素含有物質及び第二金属元素含有物質に含まれる金属元素を二価イオンとして溶融塩中に安定に存在させるために、二酸化炭素および還元性ガスを含む混合ガス雰囲気下で行う。この雰囲気下では、反応前の酸化数が二価以外の金属元素であっても二価の状態で安定に維持することが可能となる。二酸化炭素と還元性ガスの比率に特に限定はないが、還元性ガスを多く用いると、酸化雰囲気を制御する二酸化炭素が減少するため、溶融塩原料の分解が促進されて反応速度が速くなる。しかし、還元性ガスが過多では、高過ぎる還元性によりリチウムフリーシリケート系化合物の２価の金属元素が還元されて、反応生成物が破壊する恐れがある。そのため、好ましい混合ガスの混合比率は、体積比で、二酸化炭素100モルに対して還元性ガスを1〜40モルさらには3〜20モルとすることが好ましい。還元性ガスとしては、たとえば、水素、一酸化炭素などを用いることができ、水素が特に好ましい。 In the reaction described above, carbon dioxide and a reducing gas are used in order to allow the metal element contained in the first metal element-containing substance and the second metal element-containing substance to stably exist in the molten salt as divalent ions. It is performed in a mixed gas atmosphere. Under this atmosphere, even if the oxidation number before the reaction is a metal element other than divalent, it can be stably maintained in a divalent state. The ratio of carbon dioxide and reducing gas is not particularly limited. However, when a large amount of reducing gas is used, carbon dioxide for controlling the oxidizing atmosphere is reduced, so that decomposition of the molten salt raw material is promoted and the reaction rate is increased. However, if the reducing gas is excessive, the divalent metal element of the lithium-free silicate compound may be reduced due to too high reducing property, and the reaction product may be destroyed. Therefore, the preferable mixing ratio of the mixed gas is preferably 1 to 40 mol, more preferably 3 to 20 mol of the reducing gas with respect to 100 mol of carbon dioxide in volume ratio. As the reducing gas, for example, hydrogen, carbon monoxide and the like can be used, and hydrogen is particularly preferable.
二酸化炭素と還元性ガスの混合ガスの圧力については、特に限定はなく、通常、大気圧とすればよいが、加圧下、あるいは減圧下のいずれであってもよい。また反応時間は、通常、10分間〜48時間とすればよく、好ましくは30分間〜24時間さらには60分間〜12時間とすればよい。 There is no particular limitation on the pressure of the mixed gas of carbon dioxide and reducing gas, and it may be usually atmospheric pressure, but it may be under pressure or under reduced pressure. The reaction time is usually 10 minutes to 48 hours, preferably 30 minutes to 24 hours, and more preferably 60 minutes to 12 hours.
上記の反応終了後、冷却し、フラックスとして用いたアルカリ金属塩を除去することで、リチウムフリーシリケート系化合物が得られる。アルカリ金属塩を除去する方法としては、反応後の冷却により固化したアルカリ金属塩を溶解できる溶媒を用いて、生成物を洗浄することによって、アルカリ金属塩を溶解除去すればよい。たとえば、溶媒として、水を用いるとよい。このとき、反応で生成するリチウム塩も溶解除去されると考えられる。 After completion of the above reaction, the lithium-free silicate compound is obtained by cooling and removing the alkali metal salt used as the flux. As a method of removing the alkali metal salt, the alkali metal salt may be dissolved and removed by washing the product using a solvent capable of dissolving the alkali metal salt solidified by cooling after the reaction. For example, water may be used as the solvent. At this time, it is considered that the lithium salt produced by the reaction is dissolved and removed.
また、溶融塩中において、500℃以下という低温で反応を行うことによって、結晶粒の成長が抑制され、平均粒径が数μｍ以下の微細な粒子となり、さらに、不純物相の量が大きく減少する。その結果、リチウムイオン二次電池の正極活物質として用いる場合に、良好なサイクル特性およびレート特性を示すとともに高容量を有する材料となる。 In addition, by performing the reaction at a low temperature of 500 ° C. or less in the molten salt, the growth of crystal grains is suppressed, the average particle diameter becomes fine particles of several μm or less, and the amount of impurity phase is greatly reduced. . As a result, when it is used as a positive electrode active material of a lithium ion secondary battery, it becomes a material that exhibits good cycle characteristics and rate characteristics and has high capacity.
なお、平均粒径は、レーザー回折粒度分布測定装置（株式会社島津製作所製「SALD7100」など）またはTEM、SEMなどの電子顕微鏡観察によって求めることができる。たとえば、リチウムフリーシリケート系化合物を電子顕微鏡で観察し、顕微鏡写真にて識別できる粒子の寸法を複数個実測して、その数平均を求めるとよい。 The average particle size can be determined by a laser diffraction particle size distribution measuring device (such as “SALD7100” manufactured by Shimadzu Corporation) or by observation with an electron microscope such as TEM or SEM. For example, a lithium-free silicate compound is observed with an electron microscope, and a plurality of particle sizes that can be identified with a micrograph are measured, and the number average thereof is obtained.
本発明の製造方法により得られるリチウムフリーシリケート系化合物について、CuＫα線（波長1.54Å）のＸ線を用いてＸ線回折測定を行うと、回折角（2θ）が25.3°付近に現れる回折ピークと、22.7°付近に現れる回折ピークとを有し、このことによって同定することが可能である。
＜カーボン被覆処理＞
上記した方法で得られる本発明のリチウムフリーシリケート系化合物は、さらに、カーボンによる被覆処理を行って導電性を向上させてもよい。
When a lithium free silicate compound obtained by the production method of the present invention is subjected to X-ray diffraction measurement using X-rays of CuKα rays (wavelength 1.54 mm), a diffraction peak having a diffraction angle (2θ) of around 25.3 ° And a diffraction peak appearing in the vicinity of 22.7 °, which can be identified.
<Carbon coating treatment>
The lithium-free silicate compound of the present invention obtained by the above-described method may be further subjected to a coating treatment with carbon to improve conductivity.
カーボン被覆処理の具体的な方法については、特に限定的ではなく、メタンガス、エタンガス、プロパンガス、ブタンガス、アセチレンガスなどのような炭素含有ガスを含む雰囲気において熱処理を行う気相法の他、炭素源となる有機物とリチウムフリーシリケート系化合物とを均一に混合した後に熱処理によって有機物を炭化させることによる熱分解法も適用可能である。 The specific method of the carbon coating treatment is not particularly limited, and in addition to a gas phase method in which heat treatment is performed in an atmosphere containing a carbon-containing gas such as methane gas, ethane gas, propane gas, butane gas, acetylene gas, etc., a carbon source It is also possible to apply a thermal decomposition method in which an organic substance to be obtained and a lithium-free silicate compound are uniformly mixed and then carbonized by heat treatment.
特に、上記リチウムフリーシリケート系化合物に、カーボン材料を加え、ボールミルによってリチウムフリーシリケート系化合物がアモルファス化するまで均一に混合した後、熱処理を行うボールミリング法を適用することが好ましい。この方法によれば、ボールミリングによって正極活物質であるリチウムフリーシリケート系化合物がアモルファス化され、カーボンと均一に混合されて密着性が増加し、さらに熱処理により、リチウムフリーシリケート系化合物の再結晶化と同時にカーボンがリチウムフリーシリケート系化合物の周りに均一に析出して被覆することができる。 In particular, it is preferable to apply a ball milling method in which a carbon material is added to the lithium free silicate compound, and the mixture is uniformly mixed by a ball mill until the lithium free silicate compound becomes amorphous, followed by heat treatment. According to this method, the lithium-free silicate compound, which is a positive electrode active material, is made amorphous by ball milling, and is uniformly mixed with carbon to increase adhesion. Further, heat treatment recrystallizes the lithium-free silicate compound. At the same time, carbon can be uniformly deposited around the lithium-free silicate compound and coated.
この方法では、カーボン材料としては、アセチレンブラック（AB）、ケッチェンブラック（KB）、黒鉛等を用いることができる。リチウムフリーシリケート系化合物、カーボン材料の混合割合については、リチウムフリーシリケート系化合物100質量部に対して、カーボン系材料を20〜40質量部とすればよい。 In this method, acetylene black (AB), ketjen black (KB), graphite or the like can be used as the carbon material. The mixing ratio of the lithium-free silicate compound and the carbon material may be 20 to 40 parts by mass of the carbon-based material with respect to 100 parts by mass of the lithium-free silicate compound.
リチウムフリーシリケート系化合物がアモルファス化するまでボールミリング処理を行った後、熱処理を行う。熱処理は、リチウムフリーシリケート系化合物に含まれる遷移金属イオンを二価に保持するために、還元性雰囲気下で行う。この場合の還元性雰囲気としては、溶融塩中でのリチウムフリーシリケート系化合物の合成反応と同様に、二価の遷移金属イオンが金属状態まで還元されることを抑制するために、二酸化炭素と還元性ガスの混合ガス雰囲気中であることが好ましい。二酸化炭素と還元性ガスの混合割合は、リチウムフリーシリケート系化合物の合成反応時と同様とすればよい。 Ball milling is performed until the lithium-free silicate compound becomes amorphous, and then heat treatment is performed. The heat treatment is performed in a reducing atmosphere in order to keep the transition metal ions contained in the lithium-free silicate compound divalent. In this case, as the reducing atmosphere, as in the synthesis reaction of the lithium-free silicate compound in the molten salt, carbon dioxide and reducing It is preferable to be in a mixed gas atmosphere of a sex gas. The mixing ratio of carbon dioxide and reducing gas may be the same as that during the synthesis reaction of the lithium-free silicate compound.
熱処理温度は、500〜800℃とすることが好ましい。熱処理温度が低すぎる場合には、リチウムフリーシリケート系化合物の周りにカーボンを均一に析出させることが難しく、一方、熱処理温度が高すぎると、リチウムフリーシリケート系化合物の分解が生じることがあり、充放電容量が低下するので好ましくない。また、熱処理時間は、通常、1〜10時間とすればよい。
＜リチウムイオン二次電池用正極＞
本発明の製造方法により得られるリチウムフリーシリケート系化合物はもちろん、カーボン被覆処理を行ったリチウムフリーシリケート系化合物は、いずれもリチウム二次電池正極用活物質として有効に使用できる。これらのリチウムフリーシリケート系化合物を用いる正極は、通常のリチウムイオン二次電池用正極と同様の構造とすることができる。
The heat treatment temperature is preferably 500 to 800 ° C. If the heat treatment temperature is too low, it is difficult to deposit carbon uniformly around the lithium free silicate compound. On the other hand, if the heat treatment temperature is too high, decomposition of the lithium free silicate compound may occur. Since discharge capacity falls, it is not preferable. Moreover, what is necessary is just to make heat processing time into 1 to 10 hours normally.
<Positive electrode for lithium ion secondary battery>
In addition to the lithium-free silicate compound obtained by the production method of the present invention, any lithium-free silicate compound that has been subjected to carbon coating treatment can be used effectively as an active material for a lithium secondary battery positive electrode. The positive electrode using these lithium-free silicate compounds can have the same structure as a normal positive electrode for a lithium ion secondary battery.
たとえば、本発明のリチウムフリーシリケート系化合物に、アセチレンブラック（AB）、ケッチェンブラック（KB）、気相法炭素繊維（VaporGrownCarbonFiber：VGCF）等の導電助剤、ポリフッ化ビニリデン（PolyVinylidineDiFluoride：PVdF）、ポリ四フッ化エチレン（PTFE）、スチレン-ブタジエンゴム（SBR）等のバインダー、N-メチル-2-ピロリドン（NMP）等の溶媒を加えてペースト状として、これを集電体に塗布することによって正極を作製することができる。 For example, the lithium-free silicate compound of the present invention includes acetylene black (AB), ketjen black (KB), a conductive additive such as vapor grown carbon fiber (VaporGrownCarbonFiber: VGCF), polyvinylidene fluoride (PolyVinylidineDiFluoride: PVdF), By adding a binder such as polytetrafluoroethylene (PTFE) or styrene-butadiene rubber (SBR), or a solvent such as N-methyl-2-pyrrolidone (NMP), and applying it to the current collector as a paste A positive electrode can be produced.
導電助剤の使用量については、特に限定的ではないが、たとえば、リチウムフリーシリケート系化合物100質量部に対して、5〜20質量部とすることができる。また、バインダーの使用量についても、特に限定的ではないが、たとえば、リチウムフリーシリケート系化合物100質量部に対して、5〜20質量部とすることができる。また、その他の方法として、リチウムフリーシリケート系化合物と、上記の導電助剤およびバインダーを混合したものを、乳鉢やプレス機を用いて混練してフィルム状とし、これを集電体へプレス機で圧着する方法によっても正極を製造することが出来る。 The amount of the conductive auxiliary agent used is not particularly limited, but can be 5 to 20 parts by mass with respect to 100 parts by mass of the lithium-free silicate compound, for example. Further, the amount of the binder used is not particularly limited, but may be 5 to 20 parts by mass with respect to 100 parts by mass of the lithium-free silicate compound, for example. In addition, as another method, a mixture of a lithium-free silicate compound, the above-described conductive additive and binder is kneaded using a mortar or a press to form a film, which is then pressed into a current collector with a press. The positive electrode can also be produced by a method of pressure bonding.
集電体としては、特に限定はなく、従来からリチウムイオン二次電池用正極として使用されている材料、たとえば、アルミ箔、アルミメッシュ、ステンレスメッシュなどを用いることができる。さらに、カーボン不織布、カーボン織布なども集電体として使用できる。 The current collector is not particularly limited, and materials conventionally used as positive electrodes for lithium ion secondary batteries, such as aluminum foil, aluminum mesh, and stainless steel mesh, can be used. Furthermore, a carbon nonwoven fabric, a carbon woven fabric, etc. can be used as a collector.
本発明のリチウムフリーシリケート系化合物を用いたリチウムイオン二次電池用正極は、その形状、厚さなどについては特に限定的ではないが、たとえば、活物質を充填した後、圧縮することによって、厚さを10〜200μｍ、より好ましくは20〜100μｍとすることが好ましい。従って、使用する集電体の種類、構造等に応じて、圧縮後に上記した厚さとなるように、活物質の充填量を適宜決めればよい。
＜充電状態または放電状態のリチウムフリーシリケート系化合物シリケート系化合物＞
本発明のリチウムフリーシリケート系化合物はもちろん、カーボン被覆処理を行ったリチウムフリーシリケート系化合物は、これをリチウムイオン二次電池用正極活物質として用いてリチウムイオン二次電池を作製し、充電および放電を行うことによって、その結晶構造が変化する。溶融塩中で合成して得たリチウムフリーシリケート系化合物は、構造が不安定であり、充電容量も少ないが、充放電により構造が変化して安定化することによって、安定した充放電容量が得られるようになる。一旦、充放電を行ってリチウムフリーシリケート系化合物の結晶構造を変化させた後は、充電状態と放電状態でそれぞれ異なる結晶構造となるが、高い安定性を維持することができる。
＜リチウムイオン二次電池＞
上記したリチウムイオン二次電池用正極を用いるリチウムイオン二次電池は、公知の手法により製造することができる。すなわち、正極材料として、上記した正極を使用し、負極材料として、公知の金属リチウム、黒鉛などの炭素系材料、シリコン薄膜などのシリコン系材料、銅−錫やコバルト−錫などの合金系材料、チタン酸リチウムなどの酸化物材料を使用し、電解液として、公知のエチレンカーボネート、ジメチルカーボネート、プロピレンカーボネート、ジメチルカーボネートなどの非水系溶媒に過塩素酸リチウム、LiPF6、LiBF4、LiCF3SO3などのリチウム塩を0.5mol/Lから1.7mol/Lの濃度で溶解させた溶液を使用し、さらにその他の公知の電池構成要素を使用して、常法に従って、リチウムイオン二次電池を組立てればよい。
The positive electrode for a lithium ion secondary battery using the lithium-free silicate-based compound of the present invention is not particularly limited with respect to its shape, thickness, and the like. The thickness is preferably 10 to 200 μm, more preferably 20 to 100 μm. Therefore, the filling amount of the active material may be appropriately determined so as to have the above-described thickness after compression according to the type and structure of the current collector to be used.
<Lithium-free silicate compound silicate compound in charged or discharged state>
In addition to the lithium-free silicate compound of the present invention, the lithium-free silicate compound that has undergone carbon coating treatment is used as a positive electrode active material for a lithium-ion secondary battery to produce a lithium-ion secondary battery, and is charged and discharged. As a result, the crystal structure changes. Lithium-free silicate compounds obtained by synthesis in molten salt have an unstable structure and a small charge capacity, but a stable charge / discharge capacity can be obtained by stabilizing the structure by charge / discharge. Be able to. Once charge / discharge is performed and the crystal structure of the lithium-free silicate compound is changed, the crystal structure is different between the charged state and the discharged state, but high stability can be maintained.
<Lithium ion secondary battery>
A lithium ion secondary battery using the above-described positive electrode for a lithium ion secondary battery can be produced by a known method. That is, the positive electrode described above is used as a positive electrode material, and as a negative electrode material, a known carbon-based material such as lithium, graphite, a silicon-based material such as a silicon thin film, an alloy-based material such as copper-tin or cobalt-tin, An oxide material such as lithium titanate is used, and the electrolyte is a known non-aqueous solvent such as ethylene carbonate, dimethyl carbonate, propylene carbonate, dimethyl carbonate, lithium perchlorate, LiPF 6 , LiBF 4 , LiCF 3 SO 3 A lithium ion secondary battery can be assembled according to a conventional method using a solution in which a lithium salt such as 0.5 mol / L to 1.7 mol / L is dissolved, and using other known battery components. That's fine.
以下に、本発明のリチウムフリーシリケート系化合物の製造方法の実施例を挙げて、本発明を具体的に説明する。
＜混合粉Aの調製＞
リチウムシリケート(Li2SiO3）粉末(キシダ化学社製、純度99.5％)を0.5モルと、鉄粉(高純度化学社製、純度99.9％)を0.5モルと、をエタノールと共に混合し、ボールミルを用いて500rpmで2時間ミリングした後、115℃で1時間乾燥した。
＜混合粉Bの調製＞
塩化マグネシウム(キシダ化学社製、純度98％)を0.6モルと、塩化ナトリウム(シグマアルドリッチジャパン社製、純度99.5％)を0.2モルと、塩化カリウム(キシダ化学社製、純度99.5％)を0.2モルと、を混合し、500℃に加熱して溶融させた後に急冷固化し、粉砕した後115℃で乾燥した。
＜リチウムフリーシリケート系化合物の合成＞
混合粉Aを1.1839ｇと、混合粉Bを1.1296ｇと、をエタノールと共に乳鉢でよく混合し、115℃で乾燥した。この混合粉末をアルミナ(SSA-S)坩堝に入れ、二酸化炭素と水素の混合ガス雰囲気(CO2：H2＝100：3)中にて500℃で13時間焼成した。このとき主として塩化ナトリウムと塩化カリウムとが溶融塩を形成し、その溶融塩中にて反応が進行した。反応後、反応系である炉心全体（坩堝含む）を電気炉から取り出して、混合ガスを通じたまま室温まで急冷した。
Hereinafter, the present invention will be specifically described with reference to examples of the method for producing a lithium-free silicate compound of the present invention.
<Preparation of mixed powder A>
Mix 0.5 mol of lithium silicate (Li 2 SiO 3 ) powder (Kishida Chemical Co., purity 99.5%) and 0.5 mol of iron powder (Pure Chemical Co., purity 99.9%) with ethanol, After milling at 500 rpm for 2 hours, it was dried at 115 ° C. for 1 hour.
<Preparation of mixed powder B>
Magnesium chloride (manufactured by Kishida Chemical Co., 98% purity), 0.6 mol, sodium chloride (Sigma Aldrich Japan Co., Ltd., purity 99.5%) 0.2 mol, and potassium chloride (Kishida Chemical Co., Ltd., purity 99.5%) 0.2 mol Were mixed, heated to 500 ° C. and melted, rapidly solidified, pulverized, and dried at 115 ° C.
<Synthesis of lithium-free silicate compound>
1.1839 g of mixed powder A and 1.1296 g of mixed powder B were mixed well with ethanol in a mortar and dried at 115 ° C. This mixed powder was placed in an alumina (SSA-S) crucible and fired at 500 ° C. for 13 hours in a mixed gas atmosphere of carbon dioxide and hydrogen (CO 2 : H 2 = 100: 3). At this time, sodium chloride and potassium chloride mainly formed a molten salt, and the reaction proceeded in the molten salt. After the reaction, the entire reactor core (including the crucible) as a reaction system was taken out of the electric furnace and rapidly cooled to room temperature while passing the mixed gas.
乳鉢中において得られた生成物に水(20mL)を加えて、乳棒および乳鉢を用いて擦り潰した。こうして得られた粉体から塩等を取り除くために、粉体を水に分散させてから濾過及び洗浄し、115℃で乾燥した。
＜同定＞
得られた生成物について、粉末Ｘ線回折装置により、CuＫα線（波長：1.54Å）を用いてＸ線回折測定を行った。ＸＲＤパターンを図1に示した。このＸＲＤパターンは、図1に示すように、報告されているFe2SiO4及びMg2SiO4のパターンとほぼ一致したが、回折角（2θ）が25.3°付近に現れる回折ピークと22.7°付近に現れる回折ピークとの両方を有する点でFe2SiO4及びMg2SiO4のパターンとは異なり、（Fe0.5Mg0.5）2SiO4のパターンとよく類似している。したがって得られた生成物は、（Fe1-xMgx）2SiO4で表されるリチウムフリーシリケート系化合物であると考えられる。
Water (20 mL) was added to the product obtained in the mortar and ground using a pestle and mortar. In order to remove salts and the like from the powder thus obtained, the powder was dispersed in water, filtered and washed, and dried at 115 ° C.
<Identification>
The obtained product was subjected to X-ray diffraction measurement using a CuKα ray (wavelength: 1.54 mm) with a powder X-ray diffractometer. The XRD pattern is shown in FIG. As shown in Fig. 1, this XRD pattern almost coincides with the reported pattern of Fe 2 SiO 4 and Mg 2 SiO 4 , but the diffraction angle (2θ) near 25.3 ° and the diffraction peak near 22.7 ° It differs from the pattern of Fe 2 SiO 4 and Mg 2 SiO 4 in that it has both of the diffraction peaks appearing in FIG. 2, and is very similar to the pattern of (Fe 0.5 Mg 0.5 ) 2 SiO 4 . Therefore, the obtained product is considered to be a lithium-free silicate compound represented by (Fe 1-x Mg x ) 2 SiO 4 .
そこで"ｘ"の値を求める。（Fe1-xMgx）2SiO4における組成ｘ＝0、0.5、1において、a,b,c各軸の格子定数が表1のように報告されている。格子定数の組成依存性は線形関係に従うので、各軸の格子定数をそれぞれプロットすると図2〜4のようになり、最小二乗法によって回帰式を求めた。その結果、a軸：y=-0.036x+4.7997、b軸：y=-0.165x+10.396、c軸：y=-0.061+6.0595と、それぞれ回帰式が求められた。 Therefore, the value of “x” is obtained. In the composition x = 0, 0.5, 1 in (Fe 1-x Mg x ) 2 SiO 4 , the lattice constant of each axis of a, b, c is reported as shown in Table 1. Since the composition dependence of the lattice constant follows a linear relationship, when the lattice constant of each axis is plotted, the results are as shown in FIGS. 2 to 4, and the regression equation was obtained by the least square method. As a result, regression equations were obtained for a axis: y = −0.036x + 4.7997, b axis: y = −0.165x + 10.396, and c axis: y = −0.061 + 6.0595.
得られた生成物の格子定数は、表1に示したとおりであったので、その値を回帰式に当てはめ、ｘ≒0.5が求められた。 Since the lattice constant of the obtained product was as shown in Table 1, the value was applied to the regression equation to obtain x≈0.5.
すなわち本実施例で得られた生成物は、（Fe0.5Mg0.5）2SiO4で表されるリチウムフリーシリケート系化合物であった。つまり、原料にリチウムシリケート(Li2SiO3）を用いているにも関わらず、生成物にはリチウムが含まれていない。これは、反応中にLiとMgがイオン交換したことに起因すると推察される。
＜リチウムイオン二次電池の作製＞
実施例1の方法により得られたリチウムフリーシリケート系化合物を正極活物質として用い、カーボン複合化を行った後、リチウムイオン二次電池を作製した。
That is, the product obtained in this example was a lithium-free silicate compound represented by (Fe 0.5 Mg 0.5 ) 2 SiO 4 . That is, although lithium silicate (Li 2 SiO 3 ) is used as a raw material, the product does not contain lithium. This is presumably due to ion exchange of Li and Mg during the reaction.
<Production of lithium ion secondary battery>
The lithium-free silicate compound obtained by the method of Example 1 was used as a positive electrode active material, and after carbon composite formation, a lithium ion secondary battery was produced.
カーボン複合化は下記の手順で実施した。リチウムフリーシリケート系化合物とアセチレンブラック（AB）を質量比5対4の割合で秤量し、ボールミルを用いて450rpm、5時間均一混合した。その後、二酸化炭素対水素を体積比100対3の和居合いに調製した混合ガス気流下、700℃にて2時間熱処理した。 Carbon compounding was carried out by the following procedure. Lithium-free silicate compound and acetylene black (AB) were weighed at a mass ratio of 5 to 4, and uniformly mixed using a ball mill at 450 rpm for 5 hours. Thereafter, heat treatment was performed at 700 ° C. for 2 hours in a mixed gas stream prepared by mixing carbon dioxide and hydrogen in a volume ratio of 100 to 3.
カーボン複合したリチウムフリーシリケート系化合物に対して、アセチレンブラック（AB）と、PTFEとを添加し、混練した後フィルム状にして、アルミニウム製の集電体に圧着して電極を作製し、140℃で3時間真空乾燥した。組成は、質量比でリチウムフリーシリケート系化合物：AB：PTFE＝17.1：4.4：1である。その後、エチレンカーボネート（EC）：ジメチレンカーボネート（DMC）＝3：7にLiPF6を溶解して1mol/Lとした溶液を電解液として用い、セパレータとしてポリプロピレン膜（セルガード製、Celgard2400）とガラスフィルター、負極としてリチウム金属箔を用いたコイン電池を試作した。
＜充放電試験＞
このコイン電池について、放電開始で充放電特性を評価した。試験条件は、試験温度30℃、0.01mAh/cm2にて電圧1.5〜4.5Ｖ（ただし初回充電のみ1.5〜4.8Ｖ）とした。結果を図5に示した。図5は、1〜4サイクルまでの充放電曲線図である。
Carbon composite lithium-free silicate compound was added with acetylene black (AB) and PTFE, kneaded and then filmed, and then crimped to an aluminum current collector to produce an electrode at 140 ° C And dried in vacuum for 3 hours. The composition is lithium free silicate compound: AB: PTFE = 17.1: 4.4: 1 by mass ratio. After that, a solution of LiPF 6 dissolved in ethylene carbonate (EC): dimethylene carbonate (DMC) = 3: 7 to 1 mol / L was used as the electrolyte, and a polypropylene membrane (Celgard, Celgard 2400) and glass filter as the separator Then, a coin battery using a lithium metal foil as a negative electrode was prototyped.
<Charge / discharge test>
The charge / discharge characteristics of this coin battery were evaluated at the start of discharge. The test conditions were a test temperature of 30 ° C., 0.01 mAh / cm 2, and a voltage of 1.5 to 4.5 V (1.5 to 4.8 V only for the first charge). The results are shown in FIG. FIG. 5 is a charge / discharge curve diagram from 1 to 4 cycles.
図5から、本実施例のリチウムイオン二次電池は約100mAh/gの充放電容量を発現し、またサイクル特性にも優れているので、本発明のリチウムフリーシリケート系化合物は正極活物質として有用であることが明らかである。 From FIG. 5, the lithium ion secondary battery of the present example expresses a charge / discharge capacity of about 100 mAh / g, and also has excellent cycle characteristics, so the lithium-free silicate compound of the present invention is useful as a positive electrode active material. It is clear that
Claims (11)
Li2SiO3で表される珪酸リチウム化合物と、
Fe、Co、NiおよびMnからなる群から選ばれた少なくとも一種の元素を含む第一金属元素含有物質と、
Mg、Ca、Fe、Co、Ni、Mn、ZnおよびVからなる群から選ばれた少なくとも一種の元素を含む第二金属元素含有物質と、
を350℃以上600℃以下で反応させることを特徴とするリチウムフリーシリケート系化合物の製造方法。 In a molten salt containing at least one selected from alkali metal salts, in a mixed gas atmosphere containing carbon dioxide and a reducing gas,
A lithium silicate compound represented by Li 2 SiO 3 ;
A first metal element-containing material containing at least one element selected from the group consisting of Fe, Co, Ni and Mn;
A second metal element-containing material containing at least one element selected from the group consisting of Mg, Ca, Fe, Co, Ni, Mn, Zn and V;
Is reacted at 350 ° C. or higher and 600 ° C. or lower, and a method for producing a lithium-free silicate compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011034508A JP5608856B2 (en) | 2011-02-21 | 2011-02-21 | Positive electrode active material for lithium ion secondary battery, method for producing the same, positive electrode for lithium ion secondary battery, and lithium ion secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011034508A JP5608856B2 (en) | 2011-02-21 | 2011-02-21 | Positive electrode active material for lithium ion secondary battery, method for producing the same, positive electrode for lithium ion secondary battery, and lithium ion secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2012171825A true JP2012171825A (en) | 2012-09-10 |
| JP5608856B2 JP5608856B2 (en) | 2014-10-15 |
Family
ID=46975064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011034508A Expired - Fee Related JP5608856B2 (en) | 2011-02-21 | 2011-02-21 | Positive electrode active material for lithium ion secondary battery, method for producing the same, positive electrode for lithium ion secondary battery, and lithium ion secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5608856B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014017461A1 (en) * | 2012-07-25 | 2014-01-30 | 国立大学法人京都大学 | Magnesium compound, method for producing same, positive electrode active material, positive electrode, and magnesium ion secondary battery |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0585719A (en) * | 1991-09-30 | 1993-04-06 | Kanegafuchi Chem Ind Co Ltd | Silicon-base hybrid material |
| JPH09169516A (en) * | 1995-12-22 | 1997-06-30 | Touso Sangyo Kk | Production of precursor of cobalt silicate and cobalt silicate |
| JP2001266882A (en) * | 1999-05-10 | 2001-09-28 | Hydro Quebec | Novel lithium insertion electrode materials based on orthosilicate derivatives |
| JP2007335325A (en) * | 2006-06-16 | 2007-12-27 | Kyushu Univ | Cathode active material and battery for non-aqueous electrolyte secondary battery |
| JP2008218303A (en) * | 2007-03-07 | 2008-09-18 | Kyushu Univ | Method for producing positive electrode active material for secondary battery |
| JP2008293661A (en) * | 2007-05-22 | 2008-12-04 | Nec Tokin Corp | Positive electrode for lithium secondary battery and lithium secondary battery using the same |
| WO2010089931A1 (en) * | 2009-02-04 | 2010-08-12 | 独立行政法人産業技術総合研究所 | Method for producing lithium silicate compound |
| WO2012133396A1 (en) * | 2011-03-30 | 2012-10-04 | 昭栄化学工業株式会社 | Positive electrode active material for magnesium secondary battery, magnesium secondary battery, method for manufacturing positive electrode active material for magnesium secondary battery, and method for manufacturing magnesium secondary battery |
-
2011
- 2011-02-21 JP JP2011034508A patent/JP5608856B2/en not_active Expired - Fee Related
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0585719A (en) * | 1991-09-30 | 1993-04-06 | Kanegafuchi Chem Ind Co Ltd | Silicon-base hybrid material |
| JPH09169516A (en) * | 1995-12-22 | 1997-06-30 | Touso Sangyo Kk | Production of precursor of cobalt silicate and cobalt silicate |
| JP2001266882A (en) * | 1999-05-10 | 2001-09-28 | Hydro Quebec | Novel lithium insertion electrode materials based on orthosilicate derivatives |
| JP2007335325A (en) * | 2006-06-16 | 2007-12-27 | Kyushu Univ | Cathode active material and battery for non-aqueous electrolyte secondary battery |
| JP2008218303A (en) * | 2007-03-07 | 2008-09-18 | Kyushu Univ | Method for producing positive electrode active material for secondary battery |
| JP2008293661A (en) * | 2007-05-22 | 2008-12-04 | Nec Tokin Corp | Positive electrode for lithium secondary battery and lithium secondary battery using the same |
| WO2010089931A1 (en) * | 2009-02-04 | 2010-08-12 | 独立行政法人産業技術総合研究所 | Method for producing lithium silicate compound |
| WO2012133396A1 (en) * | 2011-03-30 | 2012-10-04 | 昭栄化学工業株式会社 | Positive electrode active material for magnesium secondary battery, magnesium secondary battery, method for manufacturing positive electrode active material for magnesium secondary battery, and method for manufacturing magnesium secondary battery |
| CN102723479A (en) * | 2011-03-30 | 2012-10-10 | 昭荣化学工业株式会社 | Positive active material for rechargeable magnesium battery and rechargeable magnesium battery |
Non-Patent Citations (1)
| Title |
|---|
| JPN6013060729; Ｔ．-Ｌ． ＴＳＡＩ ｅｔ ａｌ．: 'Ｇｒｏｗｔｈ ｏｆ （ＦｅｘＭｇ１-ｘ）２ＳｉＯ４ ｓｉｎｇｌｅ ｃｒｙｓｔａｌｓ ｂｙ ｔｈｅ ｄｏｕｂｌｅ ｐａｓｓ ｆｌｏａｔｉｎｇ ｚｏｎｅ ｍｅｔｈｏｄ' Ｊｏｕｒｎａｌ ｏｆ Ｃｒｙｓｔａｌ Ｇｒｏｗｔｈ , Ｖｏｌ． １６９， Ｐａｇｅｓ ７６４-７７２ （１９９６） * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014017461A1 (en) * | 2012-07-25 | 2014-01-30 | 国立大学法人京都大学 | Magnesium compound, method for producing same, positive electrode active material, positive electrode, and magnesium ion secondary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5608856B2 (en) | 2014-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5298286B2 (en) | Method for producing lithium silicate compound | |
| JP5013622B2 (en) | Method for producing lithium borate compound | |
| JP5116177B2 (en) | Method for producing lithium silicate compound | |
| KR102718013B1 (en) | Cathode active material for lithium ion secondary battery and method for producing same, and lithium ion secondary battery | |
| JP5164287B2 (en) | Lithium silicate compound and method for producing the same | |
| TWI485919B (en) | Process for producing cathode active material for use in lithium secondary battery | |
| JP2013206679A (en) | Nonaqueous electrolyte secondary battery cathode active material and manufacturing method thereof and secondary battery | |
| WO2016042728A1 (en) | Msix (m is at least one element selected from group 3-9 elements, provided that 1/3≤x≤3)-containing silicon material and method for manufacturing same | |
| JP5364865B2 (en) | Method for producing positive electrode active material for lithium secondary battery | |
| JP2013086990A (en) | Lithium silicate compound, positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery using the same | |
| JP5505868B2 (en) | Precursor of positive electrode active material for lithium secondary battery and method for producing the same | |
| JP5110664B2 (en) | Method for producing lithium borate compound | |
| WO2013099409A1 (en) | Method for producing iron phosphate, lithium iron phosphate, electrode active material, and secondary battery | |
| JP5769140B2 (en) | Method for producing positive electrode active material for lithium secondary battery | |
| KR102239076B1 (en) | Method of Synthesizing Graphene-CNF Composite Materials by Using Carbon Dioxide | |
| JP5880996B2 (en) | Lithium manganese silicate composite, positive electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery | |
| JP4479874B2 (en) | Method for producing positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery | |
| JP5608856B2 (en) | Positive electrode active material for lithium ion secondary battery, method for producing the same, positive electrode for lithium ion secondary battery, and lithium ion secondary battery | |
| JP4305613B2 (en) | Positive electrode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery | |
| JP2004002066A (en) | Cobalt oxide particle powder, its preparation process, nonaqueous electrolyte secondary battery, cathode active material for this and its manufacturing process | |
| WO2014155408A1 (en) | Hydrogen-containing lithium silicate compound, process for producing same, positive active material for nonaqueous-electrolyte secondary battery, positive electrode for nonaqueous-electrolyte secondary battery, and nonaqueous-electrolyte secondary battery | |
| JP2017095326A (en) | M-CONTAINING SILICON MATERIAL, WHERE M IS AT LEAST ONE ELEMENT SELECTED FROM Sn, Pb, Sb, Bi, In, Zn OR Au, AND MANUFACTURING METHOD THEREFOR | |
| JP5686378B2 (en) | Hydrogen-containing lithium silicate compound and method for producing the same, and positive electrode active material for non-aqueous electrolyte secondary battery, positive electrode for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130613 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130701 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20131128 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20131210 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140207 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140422 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140512 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140715 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140718 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140805 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5608856 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |