Solid Electrolyte Electrode Sheet for Controlled Lithium Supplementation
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Solution Overview
Problem
Existing lithium supplementation methods in batteries, such as direct addition of lithium powder or foil, lead to excessive heat generation and poor SEI growth, causing battery attenuation and reduced cycle performance.
Innovation Solution
An electrode sheet with a surface-coated active material layer, featuring an intermediate solid electrolyte layer and a lithium-supplementing layer composed of self-decomposing lithium compounds, which generates lithium ions without direct contact and heat release, using magnetron sputtering and evaporation methods for layer deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium powder or lithium foil is directly added to the electrode sheet for lithium supplementation, then the lithium content is increased, but excessive heat is generated and the SEI layer cannot grow properly
Solution Approach 1:
A solid electrolyte intermediate layer is introduced between the lithium-containing compound layer and the electrode sheet. This intermediate layer acts as a mediator that enables controlled lithium ion transfer while preventing direct contact between the lithium-containing compound and the electrode sheet, thereby avoiding excessive heat generation and enabling proper SEI layer formation during the lithium supplementation process.
Solution Approach 2:
The patent changes the physical and chemical parameters of the lithium supplementation system by using a self-decomposing lithium-containing compound instead of conventional lithium powder or foil. This compound decomposes at a controlled rate to release lithium ions, transforming the rapid exothermic reaction into a gradual, controlled process that generates minimal heat and allows proper SEI layer development.
2Quantity of substance
If lithium powder or lithium foil is directly added to the electrode sheet, then lithium supplementation is achieved, but the SEI layer formation is hindered due to excessive heat
Solution Approach 1:
The solid electrolyte intermediate layer serves as a protective mediator that facilitates controlled lithium ion transfer while preventing direct contact between the lithium-containing compound and the electrode sheet. This mediation enables proper SEI layer formation by controlling the rate of lithium supplementation and preventing excessive heat generation that would otherwise hinder SEI development.
Solution Approach 2:
The patent changes the supplementation mechanism from direct lithium metal contact to controlled decomposition of a lithium-containing compound. This parameter change transforms the rapid, uncontrolled lithium release into a gradual process that maintains temperatures suitable for SEI layer formation while still achieving the desired lithium supplementation effect.
3Quantity of substance
If conventional lithium supplementation methods are used, then lithium content is increased, but battery cycle performance deteriorates due to heat and poor SEI growth
Solution Approach 1:
The solid electrolyte intermediate layer acts as a mediator that enables sustained, controlled lithium ion transfer throughout the battery cycle. This controlled release mechanism prevents the thermal degradation and SEI layer defects that occur with conventional methods, thereby maintaining battery performance over extended cycling periods and improving overall cycle life.
Solution Approach 2:
The patent changes the lithium supplementation kinetics from rapid and uncontrolled to gradual and sustained. This parameter change ensures that lithium is released at a rate that maintains electrochemical stability during cycling, preventing the performance degradation associated with heat generation and poor SEI formation, thereby extending battery cycle performance.
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
This approach slows down lithium supplementation, reduces heat generation, and enhances battery efficiency and cycle performance by preventing excessive SEI growth and electrolyte oxidation, leading to improved electrochemical performance.
Implementation Method 1
The intermediate layer includes a solid electrolyte, and the lithium-supplementing layer includes a lithium-containing compound capable of self-decomposing to generate lithium ions
Implementation Method 2
a lithium-supplementing layer is arranged on the upper surface of the intermediate layer, so that the intermediate layer may be used as an artificial SEI layer. In this way, on the one hand, it is possible to avoid heat release caused by direct contact between the lithium-supplementing layer and the electrode sheet
Implementation Method 3
an intermediate layer is first arranged on the surface of the electrode sheet by a magnetron sputtering method
Implementation Method 4
then a lithium-supplementing layer is arranged on the intermediate layer by an evaporation method
Data Source
AI summary
The invention provides an electrode sheet, the surface of the active material layer of the electrode sheet is provided with an intermediate layer and a lithium-supplementing layer, the intermediate layer includes a solid electrolyte, and the lithium-supplementing layer includes a lithium-containing compound that self-decomposes to produce lithium ions. The electrode sheet of the present invention may effectively suppress the heat generated in the lithium supplementing process, and overcome the defect of continuous consumption of active lithium ions in the continuous growth of the SEI layer. Therefore, the electrode sheet provided by the present invention has excellent lithium supplementation effect and electrochemical performance.