Background technology
Fuel cell is a kind of Blast Furnace Top Gas Recovery Turbine Unit (TRT) that chemical energy in fuel and the oxidant is converted into electric energy.It is without the overheated machine process, so be not subjected to the restriction of Carnot cycle, energy conversion efficiency is very high.Simultaneously, it is again a kind of Blast Furnace Top Gas Recovery Turbine Unit (TRT) of cleanliness without any pollution.Molten carbonate fuel cell (MCFC) is to operate in 600-700 ℃ of a kind of high temperature Blast Furnace Top Gas Recovery Turbine Unit (TRT), except having characteristics such as not being subjected to Carnot cycle restriction, capacity usage ratio height and environmental friendliness, also have the incomparable advantage of many other kind types of fuel cells, applied widely as fuel, except H
2, outside the CO, also can directly make fuel with natural gas, coal gas gasification and other hydrocarbon, need not to adopt noble metal electrode simultaneously, can reduce battery cost etc. greatly.But owing to still there is barrier film sintering, cathodic corrosion dissolving at present, anode creep and bipolar plates are corroded this four big technical barrier, and MCFC fails to enter commercialization always.
The MCFC negative electrode mainly rises provides oxidant reduction reaction active sites, and the catalytic cathode reaction provides reactant channel and transmits electronic action, so generally select the porous electronics good conductor with catalytic action for use.Traditionally, the MCFC negative electrode is the nickel porous plate.After being assembled into battery with this nickel porous plate, in the atmosphere of oxidant, its in-situ oxidation is NiO, becomes the MCFC negative electrode.But it is found that NiO easily is dissolved among the fused carbonate, cathode consumption, structure changes, and cathodic polarization constantly increases, and causes battery performance decay, the Ni that even more serious is after the dissolving
+ 2Be diffused into anode-side by barrier film, at the anode-side reduce deposition, final and negative electrode is linked to be the nickel bridge, causes battery short circuit.So the NiO dissolving of cathode material is one of principal element that influences battery life.In order to eliminate this influence, people explore new cathode material and new preparation process one after another, and Ni (or NiO) is carried out finishing or substitutes NiO fully with other cathode materials.Alternative cathode material has perovskite material, Li/Mg/Fe (Mn)/O composite material etc. particularly with LiCoO
2, LiFeO
2Deng comparatively suitable.Technology for preparing electrode also from sintering to non-sintering (soft attitude electrode) transition.
Among the clear 62-295355 of Japan Patent, Cr
2NiCl is soaked on N and HfV powder surface
2In 800 ℃ of hydrogen, reduce sintering behind the solution, as anode material; Oxidation is as cathode material in 800 ℃ of air.More than Zhi Bei negative electrode still has the Ni component, and in high-temperature molten salt, the Ni problems of dissolution still exists.High temperature sintering electrode, equipment requirements are than higher, and it is bigger particularly to prepare the large area cathode difficulty.
Set forth a kind of two-dimensional structure electrode among the USP 4891280, first is that skeleton structure is the conductive oxide of metals such as Zn, Ni, Co, Cu, and granularity is less than 10 μ m, and slightly soluble (25-500ppm) plays electric action, and constitutes the macropore of 5-25 μ m; Second portion is LiFeO
2Or LiMnO
2, granularity less than 15ppm (wt), covers the appearance of skeleton less than 10 its dissolubilities of μ m, suppresses dissolving, forms 0.1 μ m aperture simultaneously.
Among the USP 5356731 with 0.5mol LiNO
3, 0.5mol Co (NO
3)
2Be formulated as 1.5 premium on currency solution with 1.5mol citric acid and 2.25mol ammonium nitrate, evenly stir, heating evaporation reacts to ignition point, removes carbon elimination in 8 hours in 500 ℃ of following roastings, with band casting system film, again in air and CO
2Atmosphere in 800-1000 ℃ of sintering, the preparation LiCoO
2Electrode.
USP 6063141 usefulness anode oxidation methods prepare LiCoO
2, with Co
2O
3And Li
2CO
3Be feedstock production LiCoO
2, and prepare LiCoO with anode oxidation method
2And physics and chemistry NiO two-layer cathode may.Its polarization impedance is 0.2 Ω cm
2, 150mA/cm
2The time overpotential be 30mV.
WO 9728571 A1 are with Li
2CO
3Powder and metal Co powder evenly are mixed and made into film, through oversintering, handle several hours in the air stream under 400-488 ℃ of temperature, until being converted into the LiCoO with big inner surface
2Battery lead plate.
WO 9853513 A1 prepare has double-deck negative electrode, and one deck is physics and chemistry NiO, and another layer is the LiCoO of ceriumization
2, the polarization impedance of two-layer electrode is minimum with temperature effect, has than the long-term job life-span.The preparation material of the second electrode lay is the cobalt oxide and the cerium co-precipitation of activation, handles to form with lithium carbonate and entreats supernatant liquid.Suspension is coated onto on the ground floor, just forms the second electrode lay through super-dry and high temperature sintering.
WO 008702 A1 has set forth the method that contains electrolytical battery lead plate of directly preparing.Preparing negative electrode in this way can be by two layers or more multi-layered the composition, begins by LiCoO
2Make lamina membranacea with the mixture that carbonate is formed, heating makes the electrolyte fusion in heating furnace.
Eur.Pat.Appl.EP 661 767 A1 are with cobalt powder and Li
2CO
3Mixture, binding agent defoamer and solvent, with band casting technology system film on a flat board, heat treated formation LiCoO
2, partially sinter and handle the required porosity that is complementary of negative electrode among generation and the MCFC.
In the Chinese patent 97111018.2, with γ-LiAlO
2Make barrier film, make anode with porous sintered Ni-Cr plate, make negative electrode with porous sintered Ni plate, being assembled into effective area is 28cm
2Monocell.Negative electrode Ni plate is in oxidizing atmosphere, and in-situ oxidation is NiO.Under 0.9MPa, 200mA/cm
2And 300mA/cm
2During discharge, cell output voltage is respectively 0.889V and 0.760V.The monocell that repeating groups is dressed up, under 0.9MPa, 200mA/cm
2And 300mA/cm
2During discharge, cell output voltage is respectively 0.918V and 0.820V.
But, do not propose to improve LiCoO in the above-mentioned report as yet
2The effective ways that the type cathodic electricity is led.
Summary of the invention
In order to overcome the problem that exists in the known technology, the object of the present invention is to provide a kind of duplex LiCoO that has
2Type negative electrode, the cathode material of this negative electrode are LiCo
1-xM
xO
2, utilize this cathode material to make negative electrode and can greatly reduce the solubility of negative electrode in fused carbonate, improved cathode stabilization, prolonged battery life, the electricity that has improved negative electrode itself is led (its electricity leads 〉=electricity of NiO lead).
The present invention also provides the preparation method of this negative electrode.It is advanced that the present invention makes the electrode prescription, perfect in shape and function.Electrode rapid draing, its internal composition is even, and is simple to operate, reliable, and the system electrode equipment is simple, the solvent low toxicity, environmental pollution is easy to amplify for a short time, and is beneficial to large-scale production, and the quality thickness of electrode is even, and atresia is flawless.
In addition, the present invention also provides a kind of preparation to have the double-pore structure negative electrode, easily forms three-phase reaction interface at thickness hole intersection and has reduced the electrode concentration polarization, improves electrode performance and stability.
And the prepared electrode of the present invention can be externally sintered without battery, directly is used for assembled battery, promptly soft construction from part; Assembling has brought many convenience to battery, is particularly suitable for the high capacity cell assembling; Increased the inside battery ohmic contact simultaneously, improved battery performance, also avoided harsh requirement at equipment such as externally sintered a series of troublesome steps of battery and large high-temperature sintering.
Specifically, a kind of molten carbonate fuel cell duplex LiCoO provided by the invention
2The type negative electrode is prepared with cathode substrate powder, organic-compound system and inorganic pore creating material and forms with the band casting, it is characterized in that the described cathode substrate powder following structural formula of serving as reasons represents: LiCo
1-xM
xO
2, wherein among M alkali earth metal Be, Mg, Ca or the Sr one or more, x=0.05-0.10; And the weight proportion 6 of cathode substrate powder and organic object and inorganic pore creating material: 1-3.
Duplex LiCoO in the invention described above
2In the type negative electrode, it is characterized in that described organic-compound system contains the mixture more than 2 kinds or 2 kinds in binding agent, plasticizer, release agent, dispersant, defoamer or the softening agent.
In addition, at the duplex LiCoO of the invention described above
2In the type negative electrode, it is characterized in that described binding agent be polyvinyl butyral resin, plasticizer be di-n-octyl phthalate, release agent be paraffin, dispersant be fish oil, disappear the bag agent be silicone oil,
In addition, at the duplex LiCoO of the invention described above
2In the type negative electrode, the weight proportion that it is characterized in that described organic-compound system and inorganic pore creating material is 9-61: 0.5-10.
In addition, at the duplex LiCoO of the invention described above
2In the type negative electrode, it is characterized in that describedly adding organic solvent in cathode substrate powder, organic-compound system and inorganic pore creating material, it adds weight proportion is the cathode substrate powder: organic-compound system and inorganic pore creating material: organic solvent is 6: 1-3: 10-20.
In addition, has a duplex LiCoO in the invention described above
2In the type negative electrode, it is characterized in that described organic solvent ethyl ester-n-butanol mixed alcohol, its weight proportion is 0.1-10: 1.
A kind of above-mentioned duplex LiCoO provided by the invention
2The preparation method of type negative electrode, its feature is pressed following step:
1). slurry preparation step: the weight proportion of pressing above-mentioned cathode substrate powder and organic-compound system, inorganic pore creating material and organic solvent is with LiCo
1-xM
xO
2Matrix powder organic solvent and organic system join ball milling in the ball grinder, treat ball milling 10-30 hour after, add the pore creating material carbon black and continued ball milling 10-30 hour, become electrode slurry;
2). above-mentioned electrode slurry is placed on the horizontal glass plate of completing mylar, make electrode film with the band casting, electrode diaphragm covers a kind of porous material object above it when drying, these object both sides are that aperture and aperture are more, the centre is that macropore and aperture are less, be transition state, when envionmental humidity is 50-70%, send warm heating, temperature 20-40 carries out drying, time 10-60 hour;
3). on hot press, film is carried out compression process and make electrode by following condition,
Precompressed: temperature 90-140 ℃, pressure 3.0-5.0MPa, time 2-4 minute;
Final pressure: temperature 90-140 ℃, pressure 5.0-9.0MPa, time 2-4 minute.
In the preparation method of the invention described above, it is characterized in that in slurry preparation step, the electrode slurry that content by control organic-compound system and carbon black obtains heterogeneity can prepare and has the double-pore structure negative electrode, its slurry mesostroma powder, it is as follows that organic-compound system and carbon black component constitute weight portion:
(1) pore layer structure
LiCo
1-xM
xO
2:60,
Polyvinyl butyral resin (PVB): 8.0-12.0,
Di-n-octyl phthalate: 5.0-7.5,
Paraffin: 2.0-8.0,
Fish oil: 0-2.5 wherein is preferably 0.5-2.5,
Silicone oil: 0-2.0 wherein is preferably 0.5-2.0,
Glycerine: 0-8.0 wherein is preferably 0.5-8.0,
Carbon black: 1.0-1.5,
Above organic substance and carbon black content are the 15-25wt% of matrix powder;
(2) gross porosity layer structure
LiCo
1-xM
xO
2:60,
Polyvinyl butyral resin (PVB): 8.0-12.0,
Di-n-octyl phthalate: 5.0-7.5,
Paraffin: 2.0-8.0,
Fish oil: 0-2.5 wherein is preferably 0.5-2.5,
Silicone oil: 0-2.0 wherein is preferably 0.5-2.0,
Glycerine: 0-8.0 wherein is preferably 0.5-8.0,
Carbon black: 3.0-3.5,
Above organic substance and carbon black content are the 25-35wt% of matrix powder.
In addition, in the preparation method of the invention described above, the electrode that it is characterized in that utilizing the pore of described preparation and gross porosity layer structure is when precompressed, it is two-in-one to forming pore structure to have the pore structure monolithic electrode with two, or it is two-in-one to pressure formation coarse texture to have the coarse texture monolithic electrode with two, perhaps that a pore structure monolithic electrode and a coarse texture monolithic electrode is two-in-one to pressing formation to mix, face with them before the precompressed sticks together, move to after the precompressed and be cooled to room temperature in the drier gradually, take the both sides mylar then off.
In addition, in the preparation method of the invention described above, it is characterized in that the two-in-one and two-in-one thickness coupling of carrying out of coarse texture, make the approaching unanimity of gross thickness everywhere, carry out final pressure pore structure; Also can with pore structure two-in-one with the coarse texture monolithic electrode; Or coarse texture is two-in-one and the pore structure monolithic electrode; Or another pore structure monolithic electrode is attached to mixes two-in-one pore structure side, another coarse texture monolithic electrode is attached to mixes two-in-one coarse texture side, carry out the thickness coupling, make the approaching unanimity of gross thickness everywhere, carry out final pressure and be cooled to room temperature then gradually, carry out final pressure again, final pressure rear electrode thickness range is 0.2-0.6mm.
In the preparation method of the invention described above, electrode preparation and drying steps also can be undertaken by following: (1) filters slurry with 100 order stainless (steel) wires, is 0.08-0.099MPa in vacuum degree, and mixing speed is under the 30-100 rev/min of condition, deviate from bubble in the slurry, the time is 10-40 minute.(2) slurry that will outgas places on the horizontal glass plate of completing mylar, makes electrode film with the band casting.(3) prepare electrode diaphragm when the drying with the band casting, cover a kind of porous material material above it, these object both sides are that aperture and aperture are more, and the centre is that macropore and aperture are less, is the filtration state.When envionmental humidity is 50-70%, send the warm braw heating, temperature 20-40 ℃ is carried out drying, and time 10-60 hour, electrode diaphragm thickness 0.1-0.3mm.
In addition, required dried monolithic electrode is cut into certain size, in 50-75 ℃ baking oven dry 5-30 hour, on hot press, film is carried out compression process then by experiment.
In above-mentioned negative electrode of the present invention, because with LiCo
1-xM
xO
2Prepare LiCoO as host material
2The type negative electrode has substituted NiO fully.In fused carbonate, LiCoO
2Dissolution velocity is that eight to ten of NiO negative electrode/once that its electricity is led is low, electrode performance is on the low side.With semiconductor doping alkaline earth element Mg, Ca, Be, Sr etc., content is at 0.05-0.10 (atomic ratio), the LiCo after the doping
1-xM
xO
2Cathodic electricity is led and can be improved about one to five times.And increase electrode pair Li
+Ionic adsorption is adsorbed a large amount of Li
+The LiCo of ion
1-xM
xO
2Negative electrode, its electricity are led and can be improved about one to three times.Negative electrode increases substantially electricity and leads like this, has improved battery performance, has reduced the electrode dissolution velocity again simultaneously, has increased battery performance stability, extending battery life.
In addition, according to the battery testing result, polarization is mainly at negative electrode in the battery.Reducing various polarization in the negative electrode, is the important channel of improving battery performance.The present invention prepares has duplex diplopore layer negative electrode.The gross porosity layer of negative electrode is an oxidant gas diffusion path, helps the transmission of oxidant gas; The pore layer is the electrode infiltration and floods electrolytical passage, helps electrolyte and soaks into and transmit.The intersection of its diplopore floor easily forms the three-phase reaction interface district, is electrochemistry highly effective reaction district, and this compound diplopore layer electrode had both reduced concentration polarization in the electrode, increased the stability of electrode reaction again.
The porosity of pore layer is less than 50%, and less than 10 μ m, and the voidage of gross porosity layer is greater than 50% near the average pore size of barrier film for its average pore size, and average pore size is greater than 10 μ m.On electrolyte distribution, be easy to reach balance between this duplex diplopore layer negative electrode and anode, the barrier film.
Among the present invention, in order to prepare the electrode layer in different apertures, add the time of carbon black when the content of carbon black of strict control organic-compound system and ball milling slurry.For the gross porosity layer, require content of organics than higher, but the too high meeting of content of organics cause electrode deflection when hot pressing to increase, for fear of electrode deformation when the hot pressing, can suitably add a part of carbon black in the slurry final stage of ball milling coarse texture.And, can add the part carbon black in the interstage of ball milling slurry for preparation pore layer.
The slurry band that will outgas casts to be completed on the mylar horizontal glass plate, controls the dry processing of rapid-curing cutback.Because LiCoO
2Type cathode substrate powder proportion is bigger, when electrode diaphragm is dry, improve rate of drying, avoids the powder particle sinking speed to strengthen caused film body solid phase particles skewness.When dry, cover a kind of porous material object above electrode, these object both sides are that aperture and aperture are more, and the centre is that macropore and aperture are less, is transition state.Formed two saturated solvent vapor spaces like this, one is at electrode diaphragm therewith between the object, and another is at this interior of articles.Reach dynamic equilibrium when making ethanol-n-butanol solvent evaporates, both improved rate of drying, prevent that again evaporation rate from causing that too soon electrode breaks or macropore occurs through these two spaces.When envionmental humidity is 50-70%, send the warm braw heating, temperature 20-40 ℃ is carried out drying, and time 10-60 hour, film thickness 0.1-0.3mm.
It is advanced that the present invention makes the electrode prescription, perfect in shape and function.Electrode rapid draing, its internal composition is even, and is simple to operate.Reliably, the system electrode equipment is simple, preparation technology advanced person, reliable, and the solvent low toxicity, environmental pollution is little, is easy to amplify, and is beneficial to large-scale production.The electrode quality thickness of preparation is even, and atresia is flawless.By the present invention, can prepare gross porosity, pore diplopore layer electrode, according to the battery needs, can be with gross porosity layer and pore layer combination in any, flexible and convenient operation.
In addition, the prepared negative electrode of the present invention can directly be used for assembled battery without the ground battery is externally sintered after hot pressing.When assembling, soft attitude negative electrode directly contacts with soft attitude barrier film, reduce internal stress variation and battery assembling force and changed the possibility that causes membrane ruptures, control speed heats up under logical oxygen condition, volatilization of organic substance and carbon black and burning in the electrode, electrode forms double-pore structure, its volume contraction, become porous body after organic substance volatilization and the burning in the battery diaphragm, its volume also will shrink.Therefore the volume total shrinkage of soft-component will surpass 15% in the battery.Be the contraction of soft-component in the balancing battery, negative electrode will exceed sealing surface 0.10-0.15mm, (porous sintered Ni negative electrode exceeds sealing surface 0.05-0.10mm).Good through the inside battery ohmic contact that the overcompensation soft-component shrinks, battery performance is higher.
Therefore, the present invention prepares electrode, has avoided outside a series of ponds the loaded down with trivial details step of preparation and to the harsh requirement of appliance arrangements such as large high-temperature sintering furnace, logical oxygen in-situ sintering becomes negative electrode in battery, has opened up a preparation electrode new way.Because the negative electrode of preparation is soft attitude film, be convenient to the tight power control of battery assembling and battery system, also increased the ohmic contact of parts at inside battery, reduced ohmic polarization.
Embodiment
Embodiment 1
In the ball grinder of 1 liter, add the porcelain ball of 1/3 ball grinder volume.Take by weighing 30.03 gram Co (NO
3)
26H
2O, 4.15 gram Li
2CO
3, 0.36 gram MgO adds in the ball grinder ball milling 30 hours.Dry in 120 ℃ of baking ovens then, mechanical crushing is ground, and heats up gradually from 100 ℃ to 800 ℃ in muffle furnace, and roasting 20 hours makes LiCo
0.92Mg
0.08O
2Powder.
Embodiment 2
Prepare LiCo by embodiment 1 method
0.92Mg
0.08O
2Powder.Take by weighing 20.4 gram LiCo
0.92Mg
0.08O
2Powder, 5.3 gram Ce (NO
3)
36H
2O, 10.5 gram La (NO
3)
36H
2O, ball milling obtained powder in 10 hours in the adding ball grinder.
Embodiment 3
In the ball grinder of 1 liter, add the porcelain ball of 1/3 ball grinder volume.Take by weighing 25.6 gram embodiment, 1 prepared LiCo
0.92Mg
0.08O
2Powder, 4.2 gram PVB, 2.4 gram di-n-octyl phthalates, 2.5 gram paraffin, 1 gram fish oil, 0.4 gram silicone oil, 1.5 gram glycerine, 80 gram ethanol-n-butanol solvents add in the ball grinder ball milling 30 hours.This slurry is divided into two parts, a 1.0 gram carbon blacks that add, ball milling becomes the pore structure cathode slurry after 20 hours; Another part adds 1.5 gram carbon blacks, and ball milling became the coarse texture cathode slurry in 15 hours.Filtering slurry with 100 order stainless (steel) wires, is 0.09MPa in vacuum degree, and mixing speed is under 30 rev/mins of conditions, deviates from bubble in the slurry, and the time is 15 minutes.The pore structure cathode slurry that will outgas respectively and coarse texture cathode slurry place on the horizontal glass plate of completing mylar, prepare pore structure negative electrode diaphragm and coarse texture negative electrode diaphragm with the band casting.When with drying device electrode diaphragm being carried out drying, cover a kind of porous material object above it, these object both sides are that the more centre of aperture and aperture is that macropore and aperture are less, are transition state.Send the warm braw heating during for 50-70% at envionmental humidity, temperature 30-35 ℃ is carried out, 40-50 hour drying time, electrode diaphragm thickness 0.10-0.15mm.Need by assembled battery, it is 28cm that each electrode diaphragm is cut into area
2Circle, placed 70 ℃ of baking ovens dry 24 hours.Respectively the face of two pore structure diaphragms and two coarse texture diaphragms is sticked together, precompressed is 2 minutes on 120 ℃ hot press again, and pressure is 3.5MPa.In drier, be cooled to room temperature, take off mylar with these two two-in-one on 120 ℃ hot press final pressure 2 minutes, pressure is 5.0MPa.In drier, be cooled to room temperature, take mylar off, promptly get battery duplex negative electrode, thickness 0.40mm.Pore layer maximum diameter of hole is 14.0 μ m, and gross porosity layer maximum diameter of hole is 42.0 μ m.
Select γ-LiAlO for use
2Make barrier film, area is 51cm
2, thickness is 0.68mm, and porous sintered Ni-Cr plate is made anode, and area is 28cm
2, thickness is 0.48mm; Above-mentioned LiCoO
2Type duplex negative electrode is assembled into monocell, is the gross porosity layer near the air chamber side, is the pore layer near the barrier film side.Be the contraction of compensation negative electrode and barrier film, negative electrode exceeds sealing surface 0.15mm, and anode exceeds sealing surface 0.10mm.
Logical oxygen control speed heats up, oxygen-supply quantity 2-3 liter/minute, programming rate 0.2-0.3 ℃/minute.For making carbon black completing combustion, during 450-500 ℃, the logical oxygen time is 8 hours.Place the carbonate of cathode chamber to begin fusing in advance at 493 ℃, and soak into battery diaphragm.Following 650 ℃ of battery operational temperatures is through using N
2The leak detection and inspection scurry qualified after, anode leads to H
2-CO
2Gaseous mixture (H
2/ CO
2=80/20, m/o), negative electrode leads to O
2-CO
2Gaseous mixture (O
2/ CO
2=40/60, m/o), gas effciency is 20%.Be respectively under 0.1MPa, 0.5MPa, the 0.9MPa at system operation pressure and measure battery performance.Table 1 is a repeatedly startability of battery.Fig. 1 is its battery performance when starting for the 9th time, under 0.9MPa, and 200mA/cm
2And 372mA/cm
2During discharge, cell output voltage is respectively 0.944V and 0.781V, and maximum power density is 291mW/cm
2
Table 1 battery is startability repeatedly
Embodiment 4
Utilize the powder of embodiment 2 made negative electrode powders replacement embodiment 1, and prepare LiCoO by embodiment 3 methods
2Type pore structure cathode slurry and coarse texture cathode slurry, and prepare negative electrode diaphragm, drying with the band casting.Face with two pore structure diaphragms sticks together earlier, and precompressed is 2 minutes on 120 ℃ hot press, and pressure is 3Wa.Again with this pore structure two-in-one with coarse texture diaphragm final pressure 2 minutes on 120 ℃ hot press, pressure is 5.5MPa, becomes electrode for cell, thickness 0.30mm.Select for use porous sintered Ni-Cr plate to make anode, area 28cm
2, thick 0.48mm; γ-LiAlO
2Make barrier film, its thickness is 0.86mm, and above-mentioned duplex electrode is made negative electrode, is assembled into the monocell negative electrode and exceeds sealing surface 0.03mm, and negative electrode exceeds sealing surface 0.10mm.Fig. 2 is its battery performance, under 0.9MPa, and 200mA/cm
2And 300mA/cm
2During discharge, cell output voltage is respectively 0.853V and 0.721V, and maximum power density is 216.3mW/cm
2
Comparative example 1:
By the Japanese Cr of Hitachi Co., Ltd
2N and HfV powder soak nickel chloride, and 800 ℃ of reduction of hydrogen 15 minutes, negative electrode was made in oxidation in 1 hour in 800 ℃ of air again.Battery is at 50 ℃, 150mA/cm
2Discharge, output voltage 0.82-0.85V.Battery can be stablized in 3000 hours.But the cathode dissolution problem still fails to overcome.
Comparative example 2
By having set forth a kind of two-dimensional structure electrode among the USP 4891280, first is that skeleton structure is the conductive oxide of Zn, Ni, Co, Cu etc., and granularity is less than 10 μ m, and slightly soluble (25-500ppm) plays electric action, and constitutes the macropore of 5-25 μ m; Second portion is LiFeO
2Or LiMnO
2, granularity less than 15ppm (wt), covers the appearance of skeleton less than 10 its dissolubilities of μ m, suppresses dissolving, forms 0.1 μ m aperture simultaneously.A target material shows and modifies in this invention, has moderately solved the cathode dissolution problem, has also considered the pore structure of negative electrode, and on the whole, it still is the single hole structure.
Comparative example 3
Prepare by WO 9853513 A1 and to have double-deck negative electrode, one deck is lithiumation NiO, and layer is the LiCoO of ceriumization in addition
2, the polarization impedance of two-layer electrode is minimum with temperature effect, has than active lifetime.The preparation material of the second electrode lay is the cobalt oxide and the blunt co-precipitation of activation, handles forming suspension with the acid reason.Suspension is coated onto on the ground floor, just forms the second electrode lay through super-dry and high temperature burning.This invention is effectively with the LiCoO of physics and chemistry NiO with ceriumization
2Bag comes, and has stoped the dissolving of NiO, and electrode structure still is the single hole structure, does not thoroughly solve oxygen agent diffusion and electrolyte transport problem.
Comparative example 4
Press among the USP 5356731 0.5mol LiNO
3, 0.5molCo (NO
3)
2Be formulated as 1.5 premium on currency solution with 1.5mol citric acid 2.25mol ammonium nitrate, evenly stir, heating evaporation reacts to putting, and removes carbon elimination in 8 hours in 500 ℃ of following roastings, with band casting system film, again in gas and CO
2Atmosphere in 800-1000 ℃ of sintering, the preparation LiCoO
2Electrode.Pure LiCoO
2The utmost point is different from LiCo of the present invention
1-xM
xO
2(a certain amount of chemisorbed Li
+Ion), and prepared the moon have the single hole structure.
Comparative example 5
By by Chinese patent application number: in 9711101.2, with γ-LIAlO
2Make barrier film, make anode with porous sintered Ni-Cr plate, make negative electrode with porous sintered Ni plate, being assembled into effective area is 28cm
2Monocell.Negative electrode Ni plate further is oxidized to NiO in oxidizing atmosphere.Following 650 ℃ of battery operational temperatures is through using N
2The leak detection and inspection scurry qualified after, anode leads to H
2-CO
2Gaseous mixture (H
2/ CO
2=80/20, m/o), negative electrode leads to O
2-CO
2Gaseous mixture (O
2/ CO
2=40/60, m/o) gas effciency is 20%.Be respectively under 0.1MPa, 0.5MPa, the 0.9MPa at system operation pressure and measure battery performance.Under 0.9MPa, 200mA/cm
2And 300mA/cm
2Cell output voltage is respectively 0.889V and 0.760V during discharge.The monocell that repeating groups is dressed up, under 0.9MPa, 200mA/cm
2And 300mA/cm
2During discharge, electricity ground output voltage is respectively 0.918V and 0.820V.