Pouch Battery FPC Layout for Thinner Top-Seal Protection
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Solution Overview
Problem
The thickness of pouch-type lithium-ion batteries is limited by the size of the protection board assembly stacked on the top seal, which impedes the reduction of battery thickness and affects volumetric energy density, especially in ultra-thin batteries.
Innovation Solution
The protection board assembly is redesigned with an FPC that includes a first part stacked on the top seal and a second part extending away from it, allowing large protection components to be positioned away from the top seal, reducing their thickness-related space occupation and integrating short-circuit protection structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the protection board assembly is stacked on the top seal, then the protection circuit is properly positioned, but the battery thickness increases and volumetric energy density decreases
Solution Approach 1:
The patent applies dimensionality change by moving the protection component from the thickness direction (stacked on top seal) to the length direction (disposed on the shell at the head). The FPC is extended along the length direction of the cell, allowing the protection circuit to be positioned horizontally rather than vertically, thus reducing battery thickness while maintaining protection functionality.
2Volume of stationary object
If the cell thickness is reduced to improve volumetric energy density, then battery space is optimized, but the protection board assembly cannot be properly accommodated
Solution Approach 1:
The protection board assembly is repositioned from the thickness dimension to the length dimension. The FPC extends along the length direction of the cell, and the protection component is disposed on the shell at the head of the cell, allowing the assembly to accommodate thin cells by utilizing the length direction space instead of the thickness direction.
Solution Approach 2:
The FPC is divided into a first portion connected to the electrode tab and a second portion extending to the protection component. This segmentation allows the electrical connection function and the protection component mounting function to be separated in space, enabling the protection component to be positioned away from the top seal area where it would interfere with cell thickness.
3Reliability
If large protection components are disposed on the top seal, then the protection circuit is complete, but the thickness-related space is excessive
Solution Approach 1:
Large protection components are relocated from the top seal area (thickness direction) to the head of the cell (length direction). The FPC is extended along the length direction to connect the electrode tab to the protection component disposed on the shell, allowing large components to be positioned horizontally where they do not increase battery thickness.
Data Source
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AI summary
A battery and an electronic device are provided. The battery includes a cell and a protection board assembly, where a head of the cell has a top seal, and an electrode tab of the cell extend from the top seal. The protection board assembly includes an FPC and a first protection component, where the first protection component is a protection component whose size in a thickness direction of the battery is greater than a preset threshold. The FPC includes a first part and a second part, where the first part of the FPC is configured to be disposed on the top seal of the cell in a stacked manner, and the second part of the FPC extends from the first part to a direction away from the top seal. An electrical signal loop between the cell and a mainboard is formed through connection via the FPC. The first protection component is disposed on the second part of the FPC. In this way, the first protection component whose height size is greater than the preset threshold is removed from a position of the top seal, and is disposed away from a stacking area above the top seal, so that space occupied by the protection component at the position of the top seal can be reduced, volumetric energy density of the battery can be effectively improved, and trending design requirements for lightness and thinness of a product are met.