Anode-Solid Electrolyte Assembly for Low-Resistance Solid-State Batteries
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Solution Overview
Problem
Current lithium-ion batteries using liquid electrolytes are prone to fire or explosion due to flammable organic solvents, necessitating the development of all-solid secondary batteries with solid electrolytes for enhanced safety.
Innovation Solution
An anode-solid electrolyte subassembly for all-solid secondary batteries, comprising an anode current collector, anode active material layers with specific carbon and metalloid compositions, and a solid electrolyte, including argyrodite-type sulfide electrolytes, to improve cell performance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid electrolytes are used in lithium-ion batteries, then high ionic conductivity is achieved, but fire or explosion risk increases due to flammable organic solvents
Solution Approach 1:
The patent changes the physical state of the electrolyte from liquid to solid, specifically using sulfide-based solid electrolytes. This parameter change eliminates the flammability issue inherent in liquid organic solvents while maintaining ionic conductivity necessary for battery operation
Solution Approach 2:
The patent employs composite anode structures combining carbon materials with metal or metalloid particles. This composite approach enhances lithium diffusion pathways and reduces resistance, compensating for the higher resistance typically associated with solid electrolytes
2Reliability
If solid electrolytes are used to eliminate flammable solvents, then safety is improved, but cell resistance and diffusion resistance increase
Solution Approach 1:
The patent uses composite anode materials combining carbon with metal/metalloid particles to create optimized lithium diffusion pathways. This composite structure reduces both cell resistance and diffusion resistance, addressing the typical drawbacks of solid electrolyte systems
Solution Approach 2:
The patent employs a two-layer anode active material structure where each layer has specific compositional characteristics. The first layer contains carbon with metal/metalloid particles optimized for interfacing with the solid electrolyte, while the second layer is optimized for lithium insertion/extraction, creating locally optimized conditions to minimize resistance
3Reliability
If solid electrolytes are used to replace liquid electrolytes, then fire risk is reduced, but low-temperature operating performance deteriorates
Solution Approach 1:
The composite anode structure with carbon and metal/metalloid particles creates multiple pathways for lithium ion transport. This composite architecture maintains lithium diffusion efficiency at low temperatures, improving adaptability across different operating conditions while retaining the safety benefits of solid electrolytes
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 design reduces the risk of fire, enhances high-rate capability, and improves low-temperature operating performance by minimizing lithium diffusion resistance and cell resistance.
Implementation Method 1
a solid electrolyte disposed on the anode active material layer and opposing the anode current collector
Implementation Method 2
improves low-temperature operating performance by minimizing lithium diffusion resistance
Data Source
AI summary
An anode-solid electrolyte subassembly includes an anode current collector, an anode active material layer disposed on the anode current collector, and a solid electrolyte disposed on the anode active material layer. The anode active material layer includes a first anode active material layer contacting the solid electrolyte, and a second anode active material layer contacting the anode current collector. The first anode active material layer includes a first anode active material containing: a mixture/composite of a carbon and one or more first elements selected from metals and metalloids, and the second anode active material layer includes a second anode active material containing: a mixture/composite of a carbon and one or more second elements selected from metals and metalloids, wherein the amount of the first elements is more than the amount of the second elements, and the amount of the first elements is about 25 wt % to about 80 wt % with respect to the total weight of the first anode active material.