All-Solid-State Battery Anode Structure for Uniform Lithium Deposition
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Solution Overview
Problem
All-solid-state batteries using lithium metal as a negative electrode face issues with lithium volume expansion and irreversible dendrite growth during charge and discharge, leading to low power characteristics and short-circuit phenomena.
Innovation Solution
A negative electrode structure comprising a current collector, an ion transport layer, and a negative coating layer with specific thickness ratios and compositions of amorphous carbon, metal, and binders, which includes a lithium deposition layer to facilitate uniform lithium precipitation without using lithium metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium metal is used as a negative electrode to increase energy density, then energy density is improved, but lithium volume expansion and irreversible dendrite growth occur during charge and discharge
Solution Approach 1:
The patent introduces a negative coating layer as an intermediary between the current collector and the ion transport layer. This coating layer includes amorphous carbon, metal particles, and binder, creating a buffer zone that accommodates lithium volume changes and prevents direct contact between lithium and the current collector, thereby suppressing dendrite growth while maintaining high energy density
Solution Approach 2:
The negative electrode uses a composite structure combining amorphous carbon, metal particles, and binder in the negative coating layer. This composite material approach provides both electrical conductivity and mechanical flexibility to accommodate lithium expansion, resolving the contradiction between high energy density and structural stability
2Reliability
If a layer is formed with lithium deposited on the negative electrode current collector during charging and discharging, then lithium metal usage is avoided, but low power characteristics and excessive short-circuit phenomena occur
Solution Approach 1:
The patent applies local quality by creating a negative coating layer with specific local properties (amorphous carbon, metal particles, binder) between the current collector and ion transport layer. This localized structural modification enables uniform lithium precipitation in specific regions while preventing short circuits, thereby improving power characteristics without sacrificing reliability
3Reliability
If the negative coating layer and ion transport layer thickness ratio is optimized, then electrochemical properties are improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a thickness ratio range (1:0.1 to 1:0.5) between the negative coating layer and ion transport layer, providing a parameter window that ensures excellent electrochemical properties. This parameter optimization balances performance requirements with manufacturing feasibility, reducing the stringency of precision control while maintaining superior electrochemical characteristics
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 proposed electrode structure suppresses overvoltage and dendrite formation, improving charge/discharge efficiency and cycle-life by ensuring stable lithium ion transport and preventing short circuits.
Implementation Method 1
an ion transport layer; and a negative coating layer located between the current collector and the ion transport layer
Implementation Method 2
a negative coating layer located between the current collector and the ion transport layer, and including first amorphous carbon, a metal, and a first binder
Data Source
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AI summary
The present invention relates to a negative electrode for an all-solid-state battery and an all-solid-state battery comprising same, and the negative electrode for an all-solid-state battery comprises: a current collector, an ion transport layer, and a negative coating layer positioned between the current collector and the ion transport layer and comprising first amorphous carbon, metal, and a first binder, wherein a thickness ratio of the negative coating layer and the ion transport layer is 1:0.1 to 1:0.5.