Solid-State Battery Anode Coating for Lower Interfacial Resistance
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Solution Overview
Problem
All-solid secondary batteries face challenges with high interfacial resistance between the anode and solid electrolyte, which affects battery capacity and stability, particularly due to the spring back phenomenon during high-temperature and high-pressure activation of sulfide-based solid electrolytes.
Innovation Solution
Incorporating natural graphite with an average particle diameter between 10 μm to 20 μm and an amorphous carbon coating layer as the anode material, which reduces interfacial resistance and enhances lithium ion mobility, thereby improving battery capacity and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature and high-pressure conditions are applied to activate sulfide-based solid electrolyte, then ionic conductivity is improved, but interfacial resistance increases due to spring back phenomenon
Solution Approach 1:
The patent applies pressure within a specific range (400-700 MPa) to activate the solid electrolyte and reduce interfacial resistance. By optimizing the pressure parameter, the patent achieves improved ionic conductivity while minimizing the spring back effect that causes increased interfacial resistance.
Solution Approach 2:
The patent uses a composite structure consisting of sulfide-based solid electrolyte combined with oxide-based solid electrolyte or buffer layer. This composite approach reduces interfacial resistance between the solid electrolyte and electrodes while maintaining high ionic conductivity, effectively resolving the contradiction between activation benefits and spring back harm.
2Reliability
If natural graphite with amorphous carbon coating layer is used as anode material, then interfacial resistance is reduced and lithium ion mobility is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent specifies a particle diameter range for natural graphite (5-20 μm) and controls the thickness of the amorphous carbon coating layer. By optimizing these parameters, the patent reduces interfacial resistance and improves lithium ion mobility while keeping the manufacturing process within feasible complexity limits.
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 use of natural graphite with an amorphous carbon coating layer in the anode material significantly reduces interfacial resistance and enhances battery capacity and lifespan by stabilizing lithium ion migration, even when a sulfide-based solid electrolyte is used.
Implementation Method 1
the natural graphite has an average particle diameter (D50) in a range of greater than about 10 μm to about 20 μm or less, and includes an amorphous carbon coating layer
Data Source
AI summary
An all-solid secondary battery includes a cathode; an anode including natural graphite; and a solid electrolyte layer between the cathode and the anode, wherein the natural graphite has an average particle diameter (D50) in a range of greater than about 10 μm to about 20 μm or less and includes an amorphous carbon coating layer.