Electrode Prelithiation Laminate for Uniform Lithium Transfer
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Solution Overview
Problem
The pre-lithiation process for silicon-containing negative electrodes in lithium secondary batteries faces challenges such as high initial irreversible capacity due to volume changes and surface reactions, leading to reduced battery capacity and cycle life, and existing methods like electrochemical pre-lithiation pose safety risks and increase production costs.
Innovation Solution
A pre-lithiation method involving a transfer laminate with a base layer, release layer, and lithium metal, where the lithium metal is transferred onto the electrode active material layer with specific adhesive force conditions, allowing for easy and uniform lithium deposition while preventing reverse transfer and by-product generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-containing negative electrode active material is used to improve energy density, then capacity increases, but initial irreversible capacity increases due to volume change and surface reactions
Solution Approach 1:
The patent applies pre-lithiation to the negative electrode before battery assembly, introducing additional lithium into the electrode structure in advance. This preliminary action compensates for the lithium that will be irreversibly consumed during initial charging cycles, thereby reducing the overall initial irreversible capacity loss while maintaining the high capacity benefits of silicon-containing materials
2Quantity of substance
If electrochemical pre-lithiation method is used to reduce initial irreversible capacity, then capacity is improved, but safety risks such as fire and explosion increase
Solution Approach 1:
The patent introduces a transfer laminate as an intermediary component that facilitates lithium metal transfer in a controlled manner. The laminate structure with specific adhesive forces acts as a mediator between the lithium metal source and the negative electrode, enabling safe and controlled pre-lithiation without the safety risks associated with direct electrochemical methods involving electrolyte wet processes
3Manufacturing precision
If electrochemical pre-lithiation method is used to control initial irreversible capacity, then capacity uniformity is improved, but production cost increases
Solution Approach 1:
The patent replaces the complex electrochemical pre-lithiation system with a simpler mechanical lamination process. By using a transfer laminate with controlled adhesive properties, the method achieves uniform lithium distribution through mechanical pressure and adhesion control, eliminating the need for expensive electrochemical equipment and complex electrolyte handling procedures
4Loss of energy
If lithium metal is transferred onto electrode active material layer to achieve pre-lithiation, then initial irreversible capacity is reduced, but lithium transfer safety and uniformity become difficult to control
Solution Approach 1:
The transfer laminate serves as an intermediary that enables controlled lithium metal transfer. The laminate's base layer and release layer with specific adhesive forces regulate the lithium transfer process, ensuring uniform distribution while maintaining safety. The intermediary structure prevents direct uncontrolled contact between lithium metal and the electrode active material
Solution Approach 2:
The patent controls lithium transfer uniformity by adjusting key parameters of the transfer laminate, including adhesive force strength, layer thickness, and material composition. By optimizing these parameters, the method achieves consistent and uniform lithium distribution across the electrode surface, transforming an uncontrollable process into a precisely adjustable manufacturing parameter system
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 method enables efficient and safe pre-lithiation of lithium metal on the electrode active material layer, improving surface uniformity and suppressing by-product formation, thereby enhancing battery capacity and cycle life while reducing production costs.
Implementation Method 1
a first adhesive force of a contact surface between the base layer and the release layer after applying an external pressure condition of 5 kgf/cm to 150 kgf/cm is higher than a second adhesive force of a contact surface between the electrode current collector layer and the electrode active material layer after applying the external pressure condition
Data Source
AI summary
Disclosed is a pre-lithiation method of an electrode for a lithium secondary battery, an electrode intermediate, and a lithium secondary battery including an electrode.