Lithium Foil Ring Assembly for In-Process Battery Pre-Lithiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for pre-lithiation of lithium secondary batteries are costly and inefficient, particularly in mass production, and there is a need for a method that can effectively perform pre-lithiation without a separate pre-lithiation process.
Innovation Solution
A method for preparing a lithium secondary battery that involves preparing a negative electrode with a solid electrolyte on both surfaces of a current collector, a lithium foil with an opening at its center, and disposing the negative electrode in the opening of the lithium foil such that the negative electrode tab contacts the lithium foil, allowing pre-lithiation to occur without overlapping the negative electrode and lithium foil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pre-lithiation methods are used, then lithium ions can be supplied to the negative electrode, but the process is costly and inefficient for mass production
Solution Approach 1:
The patent combines the pre-lithiation function with the main battery assembly process by integrating the lithium foil directly into the battery stack during normal assembly operations. The lithium foil is positioned to contact the negative electrode through the separator, allowing pre-lithiation to occur during the standard battery manufacturing process without requiring separate equipment or additional production steps.
Solution Approach 2:
The battery structure itself provides the pre-lithiation function through its own components. The lithium foil, separator, and negative electrode work together during normal battery assembly and initial charging cycles to automatically supply lithium ions to the negative electrode, eliminating the need for external pre-lithiation equipment or processes.
2Reliability
If a separate pre-lithiation process is implemented, then initial reversibility can be improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent merges the pre-lithiation function with the main battery assembly process by integrating the lithium foil directly into the battery stack during normal assembly operations. The lithium foil is positioned to contact the negative electrode through the separator, allowing pre-lithiation to occur during the standard battery manufacturing process without requiring separate equipment or additional production steps.
Solution Approach 2:
The lithium foil serves multiple functions: it acts as both a structural component of the battery and a source of lithium ions for pre-lithiation. The same lithium foil that provides long-term lithium supply also performs the pre-lithiation function during initial charging cycles, eliminating the need for separate pre-lithiation equipment or processes.
3Reliability
If lithium foil overlaps with negative electrode, then contact is improved, but direct contact causes harmful reactions
Solution Approach 1:
The patent introduces the separator as an intermediary layer between the lithium foil and the negative electrode. The separator allows lithium ions to pass through from the lithium foil to the negative electrode while physically preventing direct contact between the lithium metal and the electrode materials, thereby avoiding harmful reactions such as electrolyte decomposition while maintaining efficient lithium supply.
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 effective pre-lithiation of the negative electrode, improving the initial reversibility and electrochemical performance of the lithium secondary battery, while eliminating the need for a separate pre-lithiation process.
Implementation Method 1
a process of intercalating and deintercalating lithium ions from the positive electrode active material of the positive electrode into and out of the negative electrode active material of the negative electrode is repeated
Implementation Method 2
lithium intercalation and deintercalation reactions in the negative electrode active material are completely reversible
Implementation Method 3
this initial irreversible capacity loss is mainly caused by an electrolyte decomposition reaction on a surface of the negative electrode active material
Data Source
AI summary
A method of preparing a lithium secondary battery is provided which may effectively perform pre-lithiation, wherein, a closed square band-shaped lithium foil having an opening formed at a center thereof is prepared during the preparation of the lithium secondary battery, and a negative electrode is disposed in the opening of the lithium foil, but pre-lithiation of the negative electrode may be performed without a separate pre-lithiation process by disposing the negative electrode and the lithium foil so as not to overlap with each other and disposing a negative electrode tab so as to be in contact with the lithium foil.