Negative Electrode Gel Electrolyte for Expansion-Stable Battery Cycling
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Solution Overview
Problem
The volume expansion of the negative electrode plate during battery cycling leads to a decrease in kinetic performance, resulting in reduced cycling performance.
Innovation Solution
A negative electrode plate design incorporating an active layer with a specific mass ratio of gel electrolyte to liquid electrolyte, which stabilizes the liquid electrolyte during expansion, maintaining stable kinetic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the active substance expands during cycling, then the capacity utilization is improved, but the kinetic performance decreases and cycling performance is reduced
Solution Approach 1:
The patent changes the physical state of the electrolyte from purely liquid to a gel-liquid composite system. The gel electrolyte provides a stable matrix that maintains its structural parameters during expansion, while the liquid electrolyte ensures ionic conductivity. This parameter change allows the system to accommodate volume changes without compromising kinetic performance or cycling stability.
Solution Approach 2:
The patent employs a composite electrolyte system combining gel electrolyte and liquid electrolyte in specific mass ratios (7:3 to 9.5:0.5). The gel component provides mechanical stability and prevents leakage, while the liquid component maintains ion transport efficiency. This composite approach resolves the contradiction between accommodating expansion and maintaining kinetic performance.
2Quantity of substance
If the active substance expands during cycling, then the capacity utilization is improved, but the liquid electrolyte may leak due to squeezing
Solution Approach 1:
The gel electrolyte acts as an intermediary between the expanding active substance and the liquid electrolyte. It absorbs the mechanical stress of expansion and prevents direct squeezing of the liquid electrolyte, thereby eliminating the harmful leakage effect while still allowing capacity utilization through the liquid component.
Solution Approach 2:
The patent changes the physical state of part of the electrolyte from liquid to gel, which fundamentally alters its mechanical properties. The gel phase has higher viscosity and structural integrity, preventing leakage while maintaining the necessary ionic conductivity through the liquid phase component.
3Quantity of substance
If the active substance expands during cycling, then the capacity utilization is improved, but the kinetic performance of the negative electrode plate decreases
Solution Approach 1:
The composite electrolyte system maintains kinetic performance despite expansion because the liquid electrolyte component ensures rapid ion transport, while the gel component provides structural stability. This division of functions allows the system to simultaneously accommodate volume changes and maintain high ionic conductivity for fast kinetics.
Solution Approach 2:
By changing the electrolyte from purely liquid to a gel-liquid composite, the patent optimizes the balance between mechanical stability and ionic conductivity. The gel fraction provides structural parameter stability during expansion, while the liquid fraction maintains the speed parameters necessary for kinetic 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
The design enhances the cycling performance of the battery by reducing the risk of electrolyte leakage and maintaining stable kinetic performance despite active substance expansion.
Implementation Method 1
the gel electrolyte can stably fix the liquid electrolyte in the negative electrode plate, thereby reducing the risk of squeezing-induced leakage of a liquid electrolyte solution due to the expansion of the active substance
Implementation Method 2
an active substance on a negative electrode plate exhibits volume expansion to a certain extent, which may lead to a decrease in the kinetic performance of the negative electrode plate
Data Source
AI summary
A battery, the preparation of a battery, and a powered device are described. The battery includes a negative electrode plate that includes a negative electrode current collector and an active layer. The active layer is located on at least one surface of the negative electrode current collector. The active layer includes an active substance, a gel electrolyte, and a liquid electrolyte. An expansion rate of the negative electrode plate is greater than or equal to 10%. When the active substance expands during cycling, the gel electrolyte can stably fix the liquid electrolyte in the negative electrode plate, thereby reducing the risk of squeezing-induced leakage of a liquid electrolyte solution due to the expansion of the active substance. Thus, the negative electrode plate can maintain a relatively stable kinetic performance, thereby improving the cycling performance of the battery.