Negative Electrode Slurry Composition for Dendrite-Safe Lithium Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face issues with dendritic growth of lithium crystals leading to short-circuiting and poor product yield due to poor contact between the solid electrolyte layer and the negative electrode, and the formation of an oxide film on the lithium metal foil, which affects battery performance.
Innovation Solution
A negative electrode mixture is developed with solid electrolyte particles and electroconductive material particles disposed on their surfaces, forming a composite that inhibits dendritic growth by allowing lithium deposition within voids, using a specific slurry viscosity and mechanical compositing methods to ensure uniform dispersion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a solid electrolyte layer is disposed between positive and negative electrodes to improve contact, then battery capacity increases, but dendritic lithium crystal growth occurs causing short-circuiting
Solution Approach 1:
The invention uses a porous negative electrode layer containing solid electrolyte particles with controlled voidage (0.05 to 0.8). The porous structure allows lithium ions to deposit uniformly within the voids between particles, preventing dendritic growth while maintaining high battery capacity. The pore size and distribution are controlled to ensure safe lithium deposition pathways.
Solution Approach 2:
The negative electrode layer is formulated as a composite material containing solid electrolyte particles, binder, and conductive material. This composite structure combines the benefits of solid electrolyte (high capacity) with the advantages of porous architecture (dendrite suppression), achieving both high capacity and reliability.
2Manufacturing precision
If slurry viscosity is increased to improve particle dispersion, then uniform void formation improves, but productivity decreases due to difficulty in handling
Solution Approach 1:
The invention optimizes slurry viscosity to a specific range (0.5 to 5 Pa·s at 25°C) that balances dispersion quality and processability. This parameter optimization allows uniform distribution of solid electrolyte particles and formation of consistent void structures while maintaining efficient production rates and easy handling during manufacturing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution inhibits dendritic growth of lithium crystals, preventing short-circuiting and improving battery performance by ensuring uniform deposition of lithium within the voids between solid electrolyte particles, thus enhancing battery efficiency and yield.
Implementation Method 1
a lithium-free battery employing an in-situ plating-type negative electrode has been proposed, which uses LiCoO2 as the positive electrode material and Lipon as the solid electrolyte and deposits lithium metal onto the charge collector without using lithium metal foil
Implementation Method 2
The Inventor has found that an increase in slurry viscosity may pose difficulty in uniformly dispersing the solid electrolyte particles, which makes it difficult to form the voids uniformly and to deposit lithium (Li) crystals within the voids
Data Source
AI summary
Disclosed is a negative electrode mixture constituting a negative electrode layer, the negative electrode mixture containing: particles of a solid electrolyte; and particles of an electroconductive material which are disposed on a surface of the particles of the solid electrolyte. Preferably, the solid electrolyte includes a crystal phase having an argyrodite-type crystal structure. Preferably, the electroconductive material is a carbon material or a metal material. Also preferable is a slurry containing: the negative electrode mixture; a binder; and a solvent, wherein the slurry has a viscosity of from 0.05 to 3 Pa·s at 25°C and at a shear rate of 10 (1/s).