Elastically Compliant Battery Terminal for Reliable Electrical Connections
Solution Overview
Problem
Conventional battery systems face challenges with elevated temperatures during welding, which can damage cells, and labor-intensive mechanical connections that are prone to over/under tightening, making servicing expensive and difficult, especially for Lithium-ion cells.
Innovation Solution
The use of elastically compliant terminals with a conductive pad or foam layer between the terminal and the cell housing, allowing for lower resistance contact and reduced manufacturing costs by accommodating manufacturing variations and providing a spring force for enhanced contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is used to make electrical connections between battery cells, then strong and reliable electrical connections are achieved, but elevated temperatures are introduced that can damage the cell and potentially cause explosion
Solution Approach 1:
The patent replaces the thermal welding process with a mechanical compression system. A compliant terminal with integrated spring mechanism applies continuous mechanical pressure to maintain electrical contact between cells, eliminating the need for welding and avoiding temperature-related damage while ensuring reliable electrical connections.
Solution Approach 2:
The compliant terminal acts as an intermediary component between battery cells. It includes a spring mechanism that provides controlled compression force and a conductive element that ensures electrical connectivity, mediating the connection without direct welding between cells and thus preventing thermal damage.
2Object-affected harmful factors
If mechanical fastening methods are used to connect bus bars to cell terminals, then welding is avoided and temperature damage is prevented, but the process becomes labor-intensive and prone to over or under tightening
Solution Approach 1:
The compliant terminal is designed as a self-adjusting component. The integrated spring mechanism automatically maintains optimal compression force on the cell terminals without requiring manual adjustment during assembly. This self-service feature eliminates the need for precise torque control and reduces labor intensity while preventing over or under tightening.
Solution Approach 2:
The terminal incorporates a dynamic spring mechanism that automatically adjusts to maintain consistent electrical contact pressure. This dynamic compliance compensates for manufacturing variations and cell expansion/contraction, simplifying the assembly process and eliminating the need for precise manual fastening.
3Reliability
If rigid terminals are fixed precisely to cell housings, then stable electrical connections are achieved, but manufacturing precision requirements increase and servicing becomes difficult
Solution Approach 1:
The patent changes the mechanical parameters of the terminal from rigid to compliant. The spring mechanism provides controlled compliance that accommodates manufacturing tolerances and cell dimensional variations, reducing the need for high-precision terminal positioning while maintaining stable electrical connections.
Solution Approach 2:
The compliant terminal incorporates flexible elements including a spring mechanism and potentially flexible conductive materials. This flexibility allows the terminal to adapt to slight variations in cell dimensions and positioning, reducing manufacturing precision requirements while ensuring reliable electrical contact.
4Reliability
If individual cells are welded into the battery system, then strong electrical connections are established, but replacement of individual cells becomes expensive and difficult
Solution Approach 1:
The compliant terminal design with its spring mechanism and modular structure allows for easier cell replacement. The mechanical compression connection can be more easily disconnected and reconnected compared to welded joints, enabling individual cell replacement without requiring complex welding operations and reducing servicing costs.
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 solution reduces the risk of cell damage from elevated temperatures and simplifies the connection process, lowering manufacturing costs and improving contact reliability.
Implementation Method 1
an elastically compliant terminal that extends through the cell housing and is electrically connected to the electrode assembly. The terminal includes a first end that is connected to the electrode assembly, and a second end that is configured to form an electrical connection with an adjacent electrical conductor
Implementation Method 2
The terminal includes a compliant portion disposed between the terminal first end and the cell housing
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A battery system includes a first battery cell that is electrically connected to a second battery cell via directed contact between compliant terminals of the first and second battery cells. The compliant terminals include a first end that is electrically connected an electrode assembly disposed within the cell, a second end disposed outside the cell, and an elastically compliant portion disposed between the second end and a cell housing.