Anode Active Material for All-Solid-State Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state batteries face challenges with the use of solid electrolytes due to physical and chemical reactions at the interface with active materials, leading to suboptimal electrochemical performance and safety concerns, particularly with carbon-based anode materials having low theoretical capacity and silicon-based materials experiencing high irreversible capacity and volume expansion.
Innovation Solution
An anode active material comprising a carbon-based material with a coating layer and a silicon-based material containing nitrogen, where the carbon-based material includes particles with an average diameter of 10 μm or less and a 15 nm to 20 nm coating layer, and the silicon-based material has an average diameter of 200 nm to 300 nm, is used, with the silicon-based material synthesized using silane and ammonia gases and heat-treated in a nitrogen atmosphere, to enhance interfacial stability and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid electrolyte is used instead of a liquid electrolyte, then safety is improved, but electrochemical performance deteriorates due to physical and chemical reactions at the interface
Solution Approach 1:
A coating layer comprising amorphous carbon is formed on the surface of carbon-based particles to act as an intermediary between the solid electrolyte and the anode active material. This coating layer prevents direct physical and chemical reactions at the interface while maintaining electrochemical performance, thereby resolving the contradiction between safety improvement and performance deterioration
Solution Approach 2:
The anode active material is designed as a composite comprising carbon-based particles with a coating layer and silicon-based material. This composite structure combines the safety benefits of solid electrolytes with maintained electrochemical performance by preventing harmful interfacial reactions while enabling high capacity
2Reliability
If carbon-based material is used as anode active material, then safety is maintained, but capacity is limited to about 400 mAh/g
Solution Approach 1:
The anode active material is designed as a composite comprising carbon-based particles with a coating layer and silicon-based material. This composite structure combines the safety benefits of carbon-based materials with the high capacity of silicon-based materials, achieving both safety and high capacity simultaneously
3Quantity of substance
If silicon-based material is used to improve capacity, then energy density increases, but irreversible capacity and volume expansion increase
Solution Approach 1:
Nitrogen is doped into specific regions of the silicon-based material to create local structural improvements. This nitrogen doping enhances the structural stability of silicon-based material during electrochemical cycling, reducing volume expansion and irreversible capacity while maintaining high energy density
Solution Approach 2:
The anode active material is designed as a composite comprising carbon-based particles with a coating layer and nitrogen-containing silicon-based material. This composite structure combines the high energy density of silicon with the structural stability provided by nitrogen doping, resolving the contradiction between energy density and structural stability
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 improves the charge/discharge capacity and lifetime of all-solid-state batteries by preventing side reactions at the interface and providing superior structural stability during electrochemical cycling, resulting in enhanced performance and prolonged battery life.
Implementation Method 1
a coating layer formed on the surface of the carbon-based particles and including amorphous carbon
Implementation Method 2
a silicon-based material, which contains nitrogen (N) and thus exhibits superior structural stability upon electrochemical charging and discharging
Implementation Method 3
manufacturing a carbon-based material by forming a coating layer including amorphous carbon from a hydrocarbon gas on the surface of carbon-based particles through thermal chemical vapor deposition
Data Source
AI summary
An embodiment anode active material for an all-solid-state battery includes a carbon-based material including carbon-based particles and a coating layer formed on a surface of the carbon-based particles, the coating layer comprising amorphous carbon, and a silicon-based material. An embodiment method of manufacturing an anode active material for an all-solid-state battery includes manufacturing a carbon-based material by forming a coating layer including amorphous carbon from a hydrocarbon gas on a surface of carbon-based particles through thermal chemical vapor deposition, manufacturing a silicon-based material through thermal chemical vapor deposition using a feed comprising silane gas and ammonia gas, and mixing the carbon-based material and the silicon-based material.