CN103247823B - All-solid lithium-ion battery and preparation method thereof - Google Patents

Abstract

The invention provides a kind of all-solid lithium-ion battery and preparation method thereof.This all-solid lithium-ion battery comprises: positive electrode, plus plate current-collecting body, solid electrolyte material, negative material, negative current collector and stainless steel casing, wherein, solid electrolyte material is at least one in lithium zirconate lanthanum, strontium doping lithium zirconate lanthanum, Ge-doped lithium zirconate lanthanum, aluminium doping lithium zirconate lanthanum or silicon doping lithium zirconate lanthanum.The manufacturing process of this battery is simple, and cost is low, it is little to consume energy, in the lithium battery technology and market in future, have great application prospect.

Description

All solid lithium ion battery and preparation method thereof

technical field

The invention relates to the field of electrochemistry, in particular to an all-solid lithium ion battery and a preparation method thereof.

Background technique

Since its commercialization in the early 1990s, lithium-ion batteries have gradually occupied a growing market in the fields of consumer electronics, such as mobile phones, notebook computers, and digital cameras, due to their high energy density and power density. large market share. With the continuous prosperity of the national economy and the continuous improvement of modern technology, lithium-ion batteries have greatly expanded their application fields in today's society. For example, electric vehicles have emerged in recent years to reduce carbon dioxide emissions, and thin-film batteries have been produced with the miniaturization and integration of electronic devices. The improvement and perfection of lithium-ion battery technology has expanded its application fields. At the same time, new conditions of use have put forward more stringent and high-end requirements for lithium-ion batteries; the mutual influence and promotion of the two have driven the development of scientific research and industrial economy. Make progress together.

At present, liquid electrolytes are widely used in commercial lithium-ion batteries on the market. It is a flammable and explosive organic substance, which has safety hazards such as leakage and explosion when the temperature is too high, and will cause greater personal injury and economic losses. At the same time, for some extreme environments, such as highly integrated small electronic products and high-energy, stable energy storage power stations, etc., the existing lithium-ion battery technology has been severely challenged. Lithium battery safety accidents have occurred frequently, and lithium battery electric vehicle fire accidents have also hindered the development of commercial power lithium batteries.

Therefore, the development of lithium-ion batteries remains to be further developed.

Contents of the invention

The present invention aims at solving one of the above technical problems at least to a certain extent or at least providing a useful commercial choice. For this reason, an object of the present invention is to propose an all-solid lithium ion battery. The all-solid-state lithium-ion battery has good thermal stability, chemical stability and machinability, so it can fundamentally prevent liquid leakage and explosion, so that the safety performance can be fundamentally guaranteed.

According to the first aspect of the embodiments of the present invention, the present invention provides an all-solid-state lithium-ion battery, comprising: a positive electrode material, a positive electrode current collector, a solid electrolyte material, a negative electrode material, a negative electrode current collector, and a stainless steel casing, wherein the solid The electrolyte material is at least one of lithium lanthanum zirconate, strontium doped lithium lanthanum zirconate, germanium doped lithium lanthanum zirconate, aluminum doped lithium lanthanum zirconate or silicon doped lithium lanthanum zirconate. Since lithium lanthanum zirconate has a cubic garnet structure, it can optimize and improve electrodes and electrolytes by virtue of its high room temperature ionic conductivity (such as 10 ^-4 s/cm) and electrochemical stability (such as no reaction with metal lithium) The interfacial contact between them is expected to improve the performance of all-solid-state lithium-ion batteries, and has great application prospects.

According to the second aspect of the embodiments of the present invention, the present invention provides a method for manufacturing the above-mentioned all-solid-state lithium-ion battery, comprising the following steps: performing surface polishing treatment on the solid electrolyte material; coating the positive active material and the negative active material respectively On both sides of the surface-polished solid electrolyte material; add a positive electrode current collector and a negative electrode current collector to the outer surfaces of the positive electrode active material and the negative electrode active material respectively, so as to obtain an all-solid lithium ion battery structure; A stainless steel casing encapsulates the all-solid-state lithium-ion battery structure. The all-solid-state lithium ion battery obtained by the manufacturing method provided by the present invention greatly improves the safety of the lithium battery, and at the same time, compared with the commercial battery, it has the advantages of simple operation process, low cost, and low energy consumption. And the market has great application prospects.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural view of an all-solid-state lithium-ion battery according to an embodiment of the present invention;

Fig. 2 is the charging and discharging curve of the all-solid-state lithium-ion battery according to the embodiment of the present invention, wherein the positive pole is lithium manganate, the electrolyte is germanium-doped lithium zirconate lanthanum, the negative pole is metal lithium, and the charging and discharging voltage range is 2.3V to 4.6V. V.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

According to the first aspect of the embodiments of the present invention, the present invention provides an all-solid-state lithium ion battery, including: positive electrode material, positive electrode current collector, solid electrolyte material, negative electrode material, negative electrode current collector and stainless steel casing. According to an embodiment of the present invention, the solid electrolyte material is lithium lanthanum zirconate, strontium doped lithium lanthanum zirconate, germanium doped lithium lanthanum zirconate, aluminum doped lithium lanthanum zirconate or silicon doped lithium lanthanum zirconate at least one. Since lithium lanthanum zirconate has a cubic garnet structure, it can optimize and improve electrodes and electrolytes by virtue of its high room temperature ionic conductivity (such as 10 ^-4 s/cm) and electrochemical stability (such as no reaction with metal lithium) The interfacial contact between them is expected to improve the performance of all-solid-state lithium-ion batteries, and has great application prospects.

According to a specific embodiment of the present invention, the all-solid lithium ion battery has a layered structure. Thus, the conductivity, electrochemical stability, and safety performance of the all-solid-state lithium-ion battery can be further improved.

According to a specific embodiment of the present invention, the positive electrode material is a fluid slurry prepared in the ratio of x:(100-x-y):y (where x≥70, y≥5) by positive electrode active material, binder and conductive agent material. According to an embodiment of the present invention, the active material is at least one of lithium cobaltate, lithium manganate, nickel-cobalt-manganese ternary material, or lithium iron phosphate. Preferably, the positive electrode active material is lithium manganate. According to an embodiment of the present invention, the binder is at least one of polyvinylidene fluoride solution, polytetrafluoroethylene solution and polyvinyl alcohol solution, preferably, the binder is polyvinylidene fluoride solution. According to an embodiment of the present invention, the conductive agent is at least one of SuperP, acetylene black and graphite powder, preferably, the conductive agent is SuperP. According to an embodiment of the present invention, the proportion of the positive electrode active material is not lower than 70%, and the proportion of the conductive agent is not lower than 5%. Thus, the conductivity, electrochemical stability, and safety performance of the all-solid-state lithium-ion battery can be further improved.

According to an embodiment of the present invention, the negative electrode material is a slurry prepared with a negative electrode active material, a binder and a conductive agent according to the ratio of x:(100-x-y):y (wherein x≥70, y≥5). According to an embodiment of the present invention, the negative electrode active material is at least one of lithium metal, graphite, silicon or lithium titanate, preferably, the negative electrode material is lithium metal. According to an embodiment of the present invention, the binder is at least one of polyvinylidene fluoride solution, polytetrafluoroethylene solution and polyvinyl alcohol solution, preferably, the binder is polyvinylidene fluoride solution. According to an embodiment of the present invention, the conductive agent is at least one of SuperP, acetylene black and graphite powder, preferably, the conductive agent is SuperP. According to an embodiment of the present invention, the proportion of the negative electrode active material is not lower than 70%, and the proportion of the conductive agent is not lower than 5%. Thus, the conductivity, electrochemical stability, and safety performance of the all-solid-state lithium-ion battery can be further improved.

According to a specific embodiment of the present invention, the positive current collector is at least one of stainless steel, copper or aluminum, preferably, the positive current collector is aluminum. According to a specific embodiment of the present invention, the negative electrode current collector is at least one of stainless steel copper or aluminum, preferably, the negative electrode current collector is copper. Thus, the conductivity, electrochemical stability, and safety performance of the all-solid-state lithium-ion battery can be further improved.

According to the second aspect of the embodiments of the present invention, the present invention provides a method for manufacturing the above-mentioned all-solid-state lithium-ion battery, comprising the following steps: performing surface polishing treatment on the solid electrolyte material; coating the positive active material and the negative active material respectively On both sides of the surface-polished solid electrolyte material; add a positive electrode current collector and a negative electrode current collector to the outer surfaces of the positive electrode active material and the negative electrode active material respectively, so as to obtain an all-solid lithium ion battery structure; A stainless steel casing encapsulates the all-solid-state lithium-ion battery structure. Thus, an all-solid-state lithium-ion battery with good electrical conductivity, good electrochemical stability, and high safety performance can be obtained.

According to the embodiments of the present invention, the manner of polishing the surface of the solid electrolyte material is not particularly limited. For example, according to an example of the present invention, 200#-2000# sandpaper can be used for grinding. In this way, the surface of the solid electrolyte material with a flat and bright surface can be obtained. Thus, an all-solid-state lithium-ion battery with good electrical conductivity, good electrochemical stability, and high safety performance can be obtained.

According to the embodiments of the present invention, the manner of coating the positive active material and the negative active material on both sides of the surface-polished solid electrolyte material is not particularly limited. For example, according to specific embodiments of the present invention, the positive electrode and negative electrode materials configured in the form of a fluid slurry can be coated on the surface of the solid electrolyte. According to a specific embodiment of the present invention, when metal lithium is selected as the negative electrode material, it can be directly assembled on the surface of the solid electrolyte. Thus, an all-solid-state lithium-ion battery with good electrical conductivity, electrochemical stability, and high safety performance can be obtained.

According to the embodiment of the present invention, the all-solid-state lithium-ion battery structure is packaged with a stainless steel casing, and metal terminals are required to be connected to the positive electrode current collector and the negative electrode current collector respectively, so as to facilitate the charging and discharging process of the battery. Thus, an all-solid-state lithium-ion battery with good electrical conductivity, electrochemical stability, and high safety performance can be obtained.

According to a specific embodiment of the present invention, the all-solid lithium ion battery is a button battery or a block battery. The all-solid-state lithium ion battery obtained by the manufacturing method provided by the present invention greatly improves the safety of the lithium battery, and at the same time, compared with the commercial battery, it has the advantages of simple operation process, low cost, and low energy consumption. And the market has great application prospects.

Embodiment 1, making lithium manganate positive electrode all-solid-state lithium-ion battery

Lithium manganate is used as the positive electrode material, germanium-doped lithium lanthanum zirconate is used as the solid electrolyte, and lithium metal is used as the negative electrode material to assemble a solid lithium ion battery. First, germanium-doped lithium lanthanum zirconate was polished to smooth on 300#, 800# and 1500# sandpaper in sequence, ultrasonically treated in ethanol for 10 minutes, and dried at 70°C to obtain a solid electrolyte with a clean surface. Lithium manganese oxide, PVDF and SuperP were evenly mixed in a ratio of 80:5:15, and coated on the surface of the solid electrolyte. Paste the metal lithium sheet on the other surface of the solid electrolyte. Finally, aluminum foil and copper foil were added as current collectors on the positive side and the negative side, respectively. The above structure is packaged in a stainless steel casing to complete the production of an all-solid-state lithium-ion battery.

The all-solid-state lithium-ion battery is charged and discharged in the voltage range of 2.3V to 4.6V, and can be cycled stably for 100 times. The first charge and discharge curve is shown in Figure 2, and the first discharge capacity can reach 98mAh/g.

Embodiment 2, making lithium cobalt oxide positive electrode all-solid-state lithium-ion battery

Lithium cobaltate is used as the positive electrode material, aluminum-doped lithium lanthanum zirconate is used as the solid electrolyte, and graphite is used as the negative electrode material to assemble a solid lithium-ion battery. First, aluminum-doped lithium lanthanum zirconate was polished to smoothness on 500#, 1000# and 2000# sandpaper in sequence, ultrasonically treated in ethanol for 12 minutes, and dried at 90°C to obtain a solid electrolyte with a clean surface. Lithium cobaltate, PVA and acetylene black were mixed evenly in a ratio of 90:5:5, and coated on the surface of the solid electrolyte. Mix graphite and PVA evenly in a ratio of 95:5, and coat it on the other surface of the solid electrolyte. Finally, aluminum foil and copper foil were added as current collectors on the positive side and the negative side, respectively. The above structure is packaged in a stainless steel casing to complete the production of an all-solid-state lithium-ion battery.

The all-solid-state lithium-ion battery is charged and discharged in the voltage range of 3.0-4.3V, and can be cycled stably for 10 times, and the first discharge capacity can reach 74.4mAh/g.

Embodiment 3, making nickel-cobalt-manganese ternary positive electrode all-solid-state lithium-ion battery

A solid lithium-ion battery is assembled using nickel-cobalt-manganese ternary material as the positive electrode material, germanium-doped lithium lanthanum zirconate as the solid electrolyte, and graphite as the negative electrode material. First, germanium-doped lithium lanthanum zirconate was polished to smooth on 400#, 800# and 1500# sandpaper in sequence, ultrasonically treated in ethanol for 15 minutes, and dried at 80°C to obtain a solid electrolyte with a clean surface. The nickel-cobalt-manganese ternary material, PVDF and SuperP are uniformly mixed in a ratio of 85:5:10, and coated on the surface of the solid electrolyte. Graphite, conductive carbon black and PVDF are mixed uniformly according to the ratio of 90:5:5, and coated on the other surface of the solid electrolyte. Finally, aluminum foil and copper foil were added as current collectors on the positive side and the negative side, respectively. The above structure is packaged in a stainless steel casing to complete the production of an all-solid-state lithium-ion battery.

The all-solid-state lithium-ion battery is charged and discharged in the voltage range of 3.0V to 4.2V, and can be cycled stably for 15 times, and the first discharge capacity can reach 94.4mAh/g.

Embodiment 4, making lithium iron phosphate cathode all-solid-state lithium-ion battery

Lithium iron phosphate is used as the positive electrode material, strontium-doped lithium lanthanum zirconate is used as the solid electrolyte, and graphite is used as the negative electrode material to assemble a solid lithium ion battery. First, the strontium-doped lithium lanthanum zirconate was polished to smooth on 400#, 800# and 1500# sandpaper in sequence, ultrasonically treated in ethanol for 12 minutes, and dried at 80°C to obtain a solid electrolyte with a clean surface. Mix lithium iron phosphate, PVDF and SuperP uniformly in a ratio of 80:5:15, and coat them on the surface of the solid electrolyte. Graphite, conductive carbon black and PVDF were mixed uniformly according to the ratio of 88:5:7, and coated on the other surface of the solid electrolyte. Finally, aluminum foil and copper foil were added as current collectors on the positive side and the negative side, respectively. The above structure is packaged in a stainless steel casing to complete the production of an all-solid-state lithium-ion battery.

The all-solid-state lithium-ion battery is charged and discharged in the voltage range of 2.2V to 3.65V, and can be cycled stably for 10 times, and the first discharge capacity can reach 120.3mAh/g.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (9)

1. A method for making an all-solid-state lithium ion battery, characterized in that, the all-solid-state lithium-ion battery comprises: positive electrode material, positive electrode current collector, solid electrolyte material, negative electrode material, negative electrode current collector and stainless steel shell, Wherein, the solid electrolyte material is at least one of lithium lanthanum zirconate, strontium-doped lithium lanthanum zirconate, germanium-doped lithium lanthanum zirconate, aluminum-doped lithium lanthanum zirconate or silicon-doped lithium lanthanum zirconate, The positive electrode material is a slurry prepared from a positive electrode active material, a binder and a conductive agent, The positive electrode active material is at least one of lithium cobaltate, lithium manganate, nickel-cobalt-manganese ternary material or lithium iron phosphate; The binder is at least one of polyvinylidene fluoride solution, polytetrafluoroethylene solution and polyvinyl alcohol solution; The conductive agent is SuperP; The proportion of the positive electrode active material is not less than 70%, the proportion of the conductive agent is not less than 5%, The anode material is a slurry prepared from an anode active material, a binder and a conductive agent, The negative electrode material is metallic lithium, The binder is at least one of polyvinylidene fluoride solution, polytetrafluoroethylene solution and polyvinyl alcohol solution; The conductive agent is SuperP; The proportion of the negative electrode active material is not less than 70%, the proportion of the conductive agent is not less than 5%, The anode material is a slurry prepared from an anode active material, a binder and a conductive agent, The manufacturing method of described all-solid-state lithium-ion battery comprises the following steps: Surface polishing of solid electrolyte materials; Coating the positive electrode material and the negative electrode material on both sides of the surface-polished solid electrolyte material respectively; Adding a positive electrode current collector and a negative electrode current collector to the outer surfaces of the positive electrode material and the negative electrode material respectively, so as to obtain an all-solid lithium ion battery structure; The all-solid-state lithium-ion battery structure is packaged with a stainless steel casing. 2. The manufacturing method of the all-solid-state lithium-ion battery according to claim 1, wherein the all-solid-state lithium-ion battery is a button battery or a block battery. 3. The manufacturing method of the all-solid-state lithium-ion battery according to claim 1, wherein the all-solid-state lithium-ion battery has a layered structure. 4. The manufacturing method of an all-solid-state lithium-ion battery according to claim 1, wherein the positive electrode current collector is at least one of stainless steel, copper or aluminum. 5. The method for manufacturing an all-solid-state lithium-ion battery according to claim 4, wherein the positive electrode current collector is aluminum. 6. The method for making an all-solid-state lithium-ion battery according to claim 1, wherein the negative electrode current collector is at least one of stainless steel copper or aluminum. 7. The method for making an all-solid-state lithium-ion battery according to claim 6, wherein the negative electrode current collector is copper. 8. The manufacturing method of the all-solid-state lithium-ion battery according to claim 1, wherein the binder is a polyvinylidene fluoride solution. 9. The method for making an all-solid lithium ion battery according to claim 1, wherein the positive electrode active material is lithium manganate.