Battery Cell Lyophilic Polymer Electrolyte for Dendrite Control
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Solution Overview
Problem
Battery cells exhibit poor use reliability and cycle performance due to issues such as electrolyte solution extrusion leading to dendrite formation and short circuits, especially during volume changes caused by ion intercalation and deintercalation.
Innovation Solution
Incorporating a lyophilic polymer into the electrode assembly to form a condensed electrolyte by wrapping the electrolyte solution between molecular chains, reducing free electrolyte presence and enhancing electrolyte retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional battery cell structure is used, then the battery cell can operate, but the use reliability is poor due to dendrite formation from free electrolyte solution extrusion
Solution Approach 1:
The electrode assembly incorporates a porous structure with controlled porosity (5-50%) that acts as a physical barrier to dendrite formation while maintaining electrolyte distribution. The porous structure allows the lyophilic polymer to form a gel matrix that prevents dendrite growth pathways.
Solution Approach 2:
The invention uses a composite system combining lyophilic polymer (5-50 wt%) with conventional electrode materials to form a gel electrolyte matrix. This composite structure replaces free liquid electrolyte with a gel phase that eliminates dendrite formation while maintaining ionic conductivity.
2Reliability
If a conventional battery cell structure is used, then the battery cell can operate, but the cycle performance is poor due to electrolyte solution extrusion during volume changes
Solution Approach 1:
The invention changes the physical state of the electrolyte from liquid to gel phase by incorporating lyophilic polymer. This parameter change allows the electrolyte to maintain its functional properties while being retained within the electrode assembly structure during volume changes from ion intercalation and deintercalation.
Solution Approach 2:
The porous structure of the electrode assembly (porosity 5-50%) provides a three-dimensional network that physically retains the gel electrolyte during volume changes. The porous framework prevents electrolyte extrusion while accommodating the expansion and contraction of electrode materials during cycling.
3Reliability
If free electrolyte solution is present in the battery cell, then electrical performance can be maintained, but the risk of short circuit from dendrite formation increases
Solution Approach 1:
The invention creates a composite gel electrolyte system where lyophilic polymer (5-50 wt%) forms a three-dimensional network that traps electrolyte solution molecules. This composite structure eliminates free electrolyte while maintaining ionic conductivity through the gel matrix, preventing dendrite formation and short circuits.
Solution Approach 2:
The lyophilic polymer acts as an intermediary substance between the electrode materials and the electrolyte solution. It forms a gel matrix that mediates ion transport while physically constraining the electrolyte, preventing it from forming dendritic structures that could cause short circuits.
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
Improves battery cell reliability and electrical performance by minimizing dendrite formation and maintaining electrolyte conductivity through elastic porous slow-release mechanisms.
Implementation Method 1
the electrolyte solution can be rapidly diffused between molecular chains of the lyophilic polymer, and be wrapped by the molecular chains, after swelling and adsorption, an elastic porous slow-release electrolyte is obtained
Implementation Method 2
the electrolyte solution can be rapidly diffused between molecular chains of the lyophilic polymer
Data Source
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AI summary
A battery cell, a battery, and an electric apparatus. The battery cell comprises an electrode assembly and an electrolyte; the electrode assembly comprises a first electrode plate, a second electrode plate, and a separator; the first electrode plate and the second electrode plate have opposite polarities; the separator is arranged between the first electrode plate and the second electrode plate; at least one of the first electrode plate, the second electrode plate, and the separator comprises a lyophilic polymer; the battery cell satisfies the following formula: 0.01%≤yp1∗v1+p2∗v2+p3∗v3≤23%. wherein p1 represents a porosity of the first electrode plate; v1 represents a total volume of the first electrode plate, with a unit of µm3; p2 represents a porosity of the second electrode plate; v2 represents a total volume of the second electrode plate, with a unit of µm3; p3 represents a porosity of the separator; v3 represents a total volume of the separator, with a unit of µm3; and y represents mass of a free electrolyte solution in the battery cell, with a unit of g.