Protective Coating for Pre-Lithiated Silicon Anodes in Air
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Solution Overview
Problem
Lithium ion batteries face continuous energy decrease due to lithium consumption at the solid electrolyte interface (SEI), and pre-lithiated silicon anodes are sensitive to moisture and prone to safety issues during production, requiring expensive dry environment processing.
Innovation Solution
A pre-lithiated silicon-based anode with a protective coating is developed, where lithium is applied to the anode surface or interior, and a conductive, air-stable coating such as LiPON is formed to prevent moisture and heat reactions, allowing safe processing in air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pre-lithiation is performed to compensate for lithium loss at SEI, then initial efficiency and cycle performance are improved, but sensitivity to moisture and safety issues during production increase
Solution Approach 1:
A protective coating layer is introduced as an intermediary between the pre-lithiated silicon anode and the external environment (moisture/air). This coating acts as a barrier that prevents harmful interactions while allowing the pre-lithiation to function, thus resolving the contradiction between improved cycle performance and moisture sensitivity.
Solution Approach 2:
The protective coating is applied in advance to prevent the harmful reaction between lithium and moisture before it can occur. By establishing this protective barrier prior to battery assembly, the patent preemptively counteracts the moisture sensitivity issue while maintaining the benefits of pre-lithiation.
2Use of energy by moving object
If pre-lithiated silicon anode is used to make up lithium loss, then energy density is improved, but heat generation during lithium reaction increases
Solution Approach 1:
The protective coating serves as a thermal barrier that mediates the heat generation issue. It allows the pre-lithiation to provide energy density benefits while simultaneously controlling and reducing the heat generation during lithium reactions, thus resolving the temperature-related contradiction.
3Object-affected harmful factors
If dry environment processing is used to handle pre-lithiated anode, then moisture sensitivity is reduced, but production costs increase
Solution Approach 1:
The protective coating acts as a mediator that enables normal environment processing. By providing this protective barrier, the patent eliminates the need for expensive dry room facilities and specialized handling equipment, thus resolving the contradiction between reducing moisture sensitivity and controlling production costs.
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 energy density and cycle life of lithium ion batteries while reducing production costs by enabling safe and scalable manufacturing of pre-lithiated anodes.
Implementation Method 1
a protective coating on a surface of the silicon-based anode
Data Source
AI summary
A pre-lithiated silicon-based anode includes a silicon-based anode, lithium disposed on a surface or in an interior of the silicon-based anode, and a protective coating on the surface of the silicon-based anode. The pre-lithiated silicon-based anode allows subsequent processing to be performed safely in the atmosphere.