Prismatic Battery Electrode Assembly Shape for Higher Energy Density
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Solution Overview
Problem
Prismatic lithium-ion batteries face a reduction in energy density due to the space required for bonding the electrode assembly and terminal portion in the prismatic case, leading to inefficient use of space.
Innovation Solution
The electrode assembly is configured with a concave-convex shape, allowing for increased size and efficient arrangement of electrode plates within the case, and the use of lead tabs and insulating layers to connect terminal portions, reducing empty space and improving energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rectangular electrode plates are arranged to overlap to increase electrode assembly size, then energy efficiency is improved, but space for bonding electrode assembly and terminal portion is reduced leading to lower energy density
Solution Approach 1:
The electrode assembly is designed with a convex shape at its end portion, transforming the conventional flat rectangular structure into a curved configuration. This curvature allows the electrode assembly to fit more efficiently within the prismatic case, maximizing space utilization while maintaining the required bonding area for terminal connections, thereby resolving the contradiction between energy efficiency and energy density
2Reliability
If space is allocated for bonding electrode assembly and terminal portion in prismatic case, then electrical connection is ensured, but empty space is formed reducing energy density
Solution Approach 1:
The convex shape of the electrode assembly merges the bonding space requirement with the electrode structure itself. The protruding convex portion serves dual purposes: maintaining electrical connection functionality and utilizing the previously wasted space, thereby eliminating empty space while ensuring reliable terminal bonding
3Productivity
If electrode assembly size is increased to improve energy efficiency, then more electrode plates can be accommodated, but empty space in case increases reducing energy density
Solution Approach 1:
The convex configuration of the electrode assembly enables it to occupy the maximum available volume within the prismatic case. The curved shape allows the electrode to extend into spaces that would otherwise remain empty, thereby increasing energy efficiency without creating unused voids
Data Source
AI summary
A rechargeable battery includes a case having an internal space having one end thereof open, an electrode assembly disposed in the internal space of the case, and a cap plate coupled to the open case, wherein the electrode assembly has a concave-convex shape in a portion corresponding to the open end when a large surface thereof is viewed.