Silicon-Carbon Anode with Adhesive Layer for Volume-Change Stability
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Solution Overview
Problem
Silicon-based anode active materials in lithium secondary batteries experience significant volume changes due to lithium ion intercalation and deintercalation, leading to displacement from the anode current collector and reduced battery lifespan.
Innovation Solution
An anode design incorporating a silicon-carbon composite material with a silicon coating layer inside pores and a carbon coating layer on the surface, along with an adhesive layer and specific binders, to stabilize the anode active material and improve adhesion to the current collector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-based anode active material is used to increase capacity, then the battery capacity and energy density are improved, but the anode active material undergoes large volume change and is easily displaced from the current collector, reducing battery lifespan
Solution Approach 1:
A buffer layer is introduced between the silicon-based anode active material and the current collector. This buffer layer acts as a flexible intermediate structure that can accommodate the large volume changes of silicon during lithium ion intercalation and deintercalation, preventing the active material from detaching while maintaining electrical contact and structural integrity throughout battery cycling
Solution Approach 2:
The anode is designed as a composite structure combining silicon-based active material with a buffer layer material. This composite architecture leverages the high capacity of silicon while the buffer layer provides mechanical stability and adhesion, creating a synergistic structure that maintains both high capacity and long cycle life
2Quantity of substance
If silicon-based anode active material undergoes large volume change during lithium ion intercalation and deintercalation, then the theoretical capacity is improved, but the anode active material is easily displaced from the anode current collector
Solution Approach 1:
The buffer layer serves as an intermediary between the silicon-based anode active material and the current collector. It mediates the mechanical stress and volume changes, absorbing expansion forces during lithiation and preventing contraction-induced detachment during delithiation, thereby maintaining stable adhesion throughout the capacity cycling process
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 enhances the anode's capacity, lifespan, and rapid charging performance by reducing volume changes and improving adhesion, resulting in a lithium secondary battery with higher energy density and extended operational stability.
Implementation Method 1
silicon-based anode active material undergoes large volume change due to the intercalation and deintercalation of lithium ions
Data Source
Figure 1~2
Figure 3
AI summary
An anode for a lithium secondary battery according to exemplary embodiments of the present disclosure includes: an anode current collector; an adhesive layer formed on the anode current collector and includes a first binder; and an anode active material layer formed on the adhesive layer and includes an anode active material including silicon-carbon composite particles and a second binder. The silicon-carbon composite particles include carbon-based particles including pores, and a silicon coating layer formed inside the pores.