CN-118630138-B - Composite pole piece of soluble solid-state battery negative electrode, preparation method and application thereof

Abstract

The invention discloses a soluble solid-state battery negative electrode composite pole piece, which consists of a copper-based composite current collector and a negative electrode material active layer coated on the copper-based composite current collector, wherein the copper-based composite current collector is a soluble copper-based composite material prepared from copper powder, sodium alginate and a conductive agent, the negative electrode material active layer comprises 70-90 parts of graphite, 4-12 parts of polyvinyl alcohol, 5-13 parts of Li 7 La 3 Zr 2 O 12 and 1-5 parts of carbon black, the polyvinyl alcohol is medium molecular weight polyvinyl alcohol with the molecular weight of 120000-150000, and the preparation method and the application of the composite pole piece are disclosed.

Inventors

• WEI BINGXIN
• LIU FEI
• XIAO RONG
• LI XIYUAN
• LI SHUAI

Assignees

• 武汉船用电力推进装置研究所(中国船舶集团有限公司第七一二研究所)

Dates

Publication Date

20260512

Application Date

20240621

Claims (4)

1. 1. A soluble solid-state battery negative electrode composite pole piece is characterized by comprising a copper-based composite current collector (2) and a negative electrode material active layer (1) coated on the copper-based composite current collector (2), wherein the copper-based composite current collector (2) is a soluble copper-based composite material prepared from copper powder, sodium alginate and a conductive agent, the thickness of the copper-based composite material is 4-10 mu m, the copper-based composite material comprises 60-90wt% of copper powder, 8-38wt% of sodium alginate, 2-5wt% of the conductive agent, the copper powder consists of two different copper powders with the particle sizes of 0.2 mu m and 1.1 mu m according to the weight ratio of 1:1, the conductive agent is a mixture of graphene and carbon black with the weight ratio of 1:2, the negative electrode material active layer (1) comprises 70-90 parts of graphite, 4-12 parts of polyvinyl alcohol, 5-13 parts of Li 7 La 3 Zr 2 O 12 and 1-5 parts of a conductive agent, the polyvinyl alcohol is a medium molecular weight polyvinyl alcohol with the molecular weight of 120000-150000, the Li 7 La 3 Zr 2 O 12 is a lithium source with the Li OH 2 O as a lithium source, and the lithium source is sintered at h ℃ after the temperature is kept under the condition of 321000 ℃ to obtain a ceramic sheet.
2. 2. The soluble solid-state battery negative electrode composite pole piece according to claim 1, wherein the negative electrode material active layer (1) comprises 80 parts of graphite, 10 parts of polyvinyl alcohol, 8 parts of Li 7 La 3 Zr 2 O 12 and 2 parts of carbon black.
3. 3. A method for preparing the soluble solid-state battery negative electrode composite pole piece according to claim 1, comprising the steps of: Step 1, weighing copper powder, graphene, carbon black and sodium alginate, vibrating and mixing in a ball milling mixing pipe, uniformly mixing, adding ultrapure water, vibrating and mixing until slurry A with the viscosity of 1300-160 mpa.s is formed, coating the slurry A on a glass substrate, drying for 2-10 hours at 50-90 ℃ in a vacuum oven, rolling, and stripping to obtain a soluble copper-based composite material; Step 2, weighing graphite, li 7 La 3 Zr 2 O 12 and carbon black, dry-mixing uniformly, adding N-methyl pyrrolidone, mixing and ball milling to obtain slurry B, weighing polyvinyl alcohol, adding the polyvinyl alcohol into the slurry B, continuously using a ball mill to ball mill for 2-6 hours at the rotation rate of 300-350 r/min and revolution rate of 2-5 r/min, and using a high-shear emulsifying machine to perform high-speed stirring to obtain negative electrode active slurry; and step 3, coating the anode active slurry on a soluble copper-based composite material, drying at 40-80 ℃, and rolling by using a roll squeezer to obtain the soluble solid-state battery anode composite pole piece.
4. 4. A soluble solid state battery negative electrode composite pole piece as claimed in claim 1 for use in a lithium battery.

Description

Composite pole piece of soluble solid-state battery negative electrode, preparation method and application thereof Technical Field The invention belongs to the field of electrochemical energy storage, and particularly relates to a soluble solid-state battery negative electrode composite pole piece, a preparation method thereof and a lithium battery. Background Under the great background of the global energy revolution, lithium batteries have become an indispensable energy storage device in electronic products such as electric automobiles, smart phones, unmanned aerial vehicles and the like due to their excellent performance characteristics, such as high energy density, long cycle life and low self-discharge rate. However, with intensive research and widespread use of lithium battery technology, positive and negative electrode materials face a series of challenges and problems. The negative electrode current collector plays an important role in lithium batteries, but its limitations are increasingly prominent in certain application fields. Particularly in the scene of high safety and quick destruction self-destruction, such as military field, special equipment field, etc., the property of the negative current collector is important. However, currently commonly used anode current collector materials (such as copper or other metal alloys) tend to have lower solubility or greater stability, which results in a difficulty in achieving rapid and complete self-destruction of the battery when the battery is damaged or a specific condition is triggered, thereby increasing the risk of information leakage or safety accidents. Disclosure of Invention Aiming at the defects of the prior art, one of the purposes of the invention is to provide a novel soluble solid-state battery negative electrode composite pole piece, which is prepared by adopting a soluble material as a negative electrode current collector and coating a negative electrode active layer on the negative electrode current collector, has normal negative electrode function, can be assembled with a solid electrolyte and a corresponding positive electrode piece to form a soluble solid-state battery, and the design of the solubility of the soluble solid-state battery negative electrode composite pole piece greatly simplifies the recovery process of the battery, is beneficial to the recovery and reuse of active substances, and provides a new solution for the sustainable development of a lithium battery. The technical scheme includes that the soluble solid-state battery negative electrode composite pole piece comprises a copper-based composite current collector and a negative electrode material active layer coated on the copper-based composite current collector, wherein the copper-based composite current collector is a soluble copper-based composite material prepared from copper powder, sodium alginate and a conductive agent, the negative electrode material active layer comprises, by weight, 70-90 parts of graphite, 4-12 parts of polyvinyl alcohol, 5-13 parts of composite solid electrolyte Li 7La3Zr2O12 and 1-5 parts of carbon black, and the polyvinyl alcohol is medium-molecular-weight polyvinyl alcohol with a molecular weight of 120000-150000. Sodium alginate is adopted as a binder in the soluble copper-based composite material, so that the soluble copper-based composite material has good water solubility, the soluble copper-based composite material can be well compatible with a negative electrode active material, the interface compatibility is good, the mutual contact area is large, the negative electrode active layer adopts polyvinyl alcohol as the binder, the soluble copper-based composite material can be well dissolved in an aqueous solution, and the polarities of the polyvinyl alcohol and the sodium alginate are similar, so that the soluble copper-based composite material can be well compatible with the negative electrode active material, and the compatibility is further improved. Further, the copper-based composite current collector has a thickness of 4-10 mu m, and comprises, by weight, 60-90% of copper powder, 8-38% of sodium alginate as a binder and 2-5% of a conductive agent. Preferably, the content of copper powder is 80wt%, the content of sodium alginate is 17wt%, and the content of the conductive agent is 3wt%. Further, the copper powder consists of two different copper powders with the particle sizes of 0.2 mu m and 1.1 mu m according to the weight ratio of 1:1. Further, the conductive agent is a mixture of graphene and carbon black in a weight ratio of 1:2. The density of the composite material can be ensured by different grain size grading, the viscosity and the expansibility can be further improved, the conductivity can be improved, the graphene is a sheet material, the carbon black is granular, the granular structure and the two-position sheet structure are matched for use, the conductivity can be improved, and the strength of the composite materi