Bipolar Battery Plate Structure for Sealing and Dendrite Control
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Solution Overview
Problem
Bipolar batteries face issues with sealing to prevent electrolyte leakage and excessive dendrite formation, leading to cell failure and charge capacity degradation, particularly due to unreliable gaskets and the use of non-conductive plastic with metal vias that flex and fracture during charging and discharging.
Innovation Solution
The method involves extruding a conductive polymer core with a uniform distribution of conductive particles, which is then overmoulded with a non-conductive polymer surround, and abraded to expose conductive particles, providing a robust and conductive bipolar plate with enhanced electrical properties and structural stiffness, and using metallic layers formed by electroplating or cold spraying for improved conductivity and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional gaskets are used for sealing bipolar cells, then sealing is achieved, but the gaskets are unreliable leading to electrolyte leakage and cell failure
Solution Approach 1:
The patent removes the separate gasket component from the bipolar battery structure and integrates the sealing function directly into the bipolar plate itself through the non-conductive polymer surround, eliminating the reliability issues associated with separate gasket components
Solution Approach 2:
The sealing function is merged with the bipolar plate structure by forming an integral non-conductive polymer surround that both electrically isolates the conductive core and provides reliable sealing, combining multiple functions into a single integrated component
2Reliability
If thin non-conductive plastic plates with metal vias are used, then charge conduction is achieved, but the plates flex and fracture during charging and discharging leading to cell failure
Solution Approach 1:
The patent uses a composite structure with a conductive polymer core providing flexibility and fracture resistance, surrounded by a non-conductive polymer surround for electrical isolation and structural support, combining the benefits of both conductive and structurally robust materials
Solution Approach 2:
The patent changes the material parameters by using a flexible conductive polymer core instead of thin rigid plastic plates, and optimizes the thickness ratio between the conductive core and non-conductive surround to achieve both flexibility and structural integrity
3Reliability
If metal vias are used in non-conductive plastic plates, then charge conduction is achieved, but excessive dendrite formation occurs in the proximity of the vias leading to charge capacity degradation
Solution Approach 1:
The patent applies local quality by using a uniformly conductive polymer core throughout the plate structure, eliminating localized high-current-density regions around metal vias that cause dendrite formation, while maintaining good electrical conductivity through the entire plate
Solution Approach 2:
The patent removes the metal via components from the structure and replaces them with a uniformly conductive polymer core, eliminating the source of excessive dendrite formation while maintaining charge conduction functionality
4Productivity
If injection moulding or hot-pressing processes are used to form conductive polymer plates, then mass production is enabled, but conductive particles lag behind the molten polymer front resulting in areas with low density of conductive particles
Solution Approach 1:
The patent uses extrusion as a preliminary forming step that achieves uniform conductive particle distribution before final shaping, preventing the particle lagging problem that occurs in injection moulding and hot-pressing processes
Solution Approach 2:
The patent replaces the molten polymer flow mechanism of injection moulding with a extrusion-based forming process that maintains uniform particle distribution through controlled material transport without rapid flow front advancement
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 effectively prevents electrolyte leakage, reduces dendrite formation, and enhances the charge capacity and structural integrity of bipolar batteries by ensuring consistent conductivity and mechanical stability, allowing for more compact and reliable energy storage.
Implementation Method 1
a step of extruding a first polymer containing conductive particles to form a conductive polymer plate
Implementation Method 2
The method includes overmoulding a conductive polymer core, for example a conductive polymer core that has been formed by such an extrusion and cutting process, with a second polymer to provide the conductive polymer core with a non-conductive polymer surround
Implementation Method 3
The method may comprise the step of abrading at least one of the surfaces of the conductive polymer plate to expose the conductive particles prior to the step of cutting the conductive polymer core
Implementation Method 4
using metallic layers formed by electroplating or cold spraying for improved conductivity and adhesion
Implementation Method 5
using metallic layers formed by electroplating or cold spraying for improved conductivity and adhesion
Data Source
AI summary
A method of manufacturing a plate suitable for use as a bipolar plate 500 in a bipolar battery 1 is disclosed. The method comprises the steps of extruding a first polymer containing conductive particles to form a conductive polymer plate 505, cutting a conductive polymer core 512 from the conductive polymer plate 505, and overmoulding the conductive polymer core 512 with a second polymer to provide a non-conductive polymer surround 516. A bipolar battery 1 is also disclosed, as well as a method of making a bipolar battery 1.