Battery Module Bus Bar Bent Portion Expansion Compensation
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Solution Overview
Problem
Existing battery modules face issues with maintaining a satisfactory connection state between battery cells and bus bars due to expansion, which causes stress and increased contact resistance, potentially leading to bus bar disconnection or short circuits.
Innovation Solution
The battery module incorporates protruding walls between adjacent bus bars and a bent portion in the bus bars that can deform to extend in the arrangement direction as battery cells expand, along with an elastic member to absorb expansion load, ensuring stable connections and preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If battery cells are connected by rigid bus bars, then electrical connection is established, but stress accumulates in the bus bars due to battery expansion, leading to connection failure or increased contact resistance
Solution Approach 1:
The bus bar is designed with a bent portion that can dynamically change its shape in response to battery expansion. The bent portion deforms to follow the expansion of battery cells, transforming the rigid connection into a semi-flexible one that adapts to dimensional changes, thereby reducing stress accumulation while maintaining electrical connection reliability
Solution Approach 2:
The geometry of the bus bar is changed by introducing a bent portion with specific curvature radius and deformation characteristics. This parameter modification allows the bus bar to undergo controlled deformation within a certain range, enabling it to accommodate battery expansion without exceeding stress thresholds that would cause connection failure
2Duration of action of stationary object
If battery cells expand due to long-term use, then film formation on electrodes occurs, but the distance between adjacent battery cells increases, causing bus bar disconnection or increased contact resistance
Solution Approach 1:
The bent portion of the bus bar serves as a dynamic compensation mechanism that deforms in response to increasing distance between battery cells during service life extension. This dynamic adaptation allows the electrical connection to maintain contact pressure and conductivity even as the physical distance between cells increases over time
Solution Approach 2:
The bent portion is pre-designed with sufficient deformation capacity to accommodate the maximum expected expansion of battery cells throughout their service life. This beforehand cushioning ensures that even after long-term use and significant expansion, the bus bar maintains adequate contact without disconnection or excessive contact resistance
3Reliability
If protruding walls are added between bus bars to prevent short circuits, then safety is improved, but device complexity increases
Solution Approach 1:
The battery holder structure is designed to serve multiple functions: it provides mechanical support for battery cells, positions the bus bars, and incorporates protruding walls that simultaneously act as insulators and structural reinforcement. This multi-functionality achieves short circuit prevention without proportionally increasing device complexity
Solution Approach 2:
The protruding walls are integrated into the battery holder structure rather than being separate components. The battery holder combines mechanical support and electrical insulation functions into a single structure, reducing the total number of parts while achieving both structural integrity and short circuit prevention
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 design maintains a stable connection state between battery cells and bus bars, reduces stress on the bus bars, prevents short circuits, and minimizes contact resistance, ensuring reliable charging and discharging even with battery expansion.
Implementation Method 1
each include a bent portion that is capable of being deformed to extend in the arrangement direction as the battery cells expand
Data Source
AI summary
A battery module has battery cells. The battery cells are arranged side by side while being separately held by battery holders. The battery cells are connected in series with bus bars. Each bus bar has a bent portion. Each battery holder includes a protruding wall that is provided between connection terminals adjacent to each other in the direction in which the battery cells are arranged. The protruding walls protrude further than the connection terminals in the direction in which the connection terminals protrude from the cases.