Conductive Spring Battery Terminal Connection
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Solution Overview
Problem
Existing high-voltage battery packs with metal foil terminals face issues such as galvanic corrosion, open-circuiting, and short-circuiting due to bolted pressure connections, which are impractical for soft package lithium-ion batteries, and concentrate current over a small terminal area.
Innovation Solution
A pressure connection apparatus using a conductive spring member with aluminum and copper cladding and oppositely curved ends, sandwiched between retaining members with curved pockets, to securely connect aluminum and copper foil terminals without internal fasteners, reducing galvanic corrosion and ensuring reliable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bolted pressure connections are used to join foil terminals, then electrical connection is achieved, but galvanic corrosion occurs due to joining dissimilar metals
Solution Approach 1:
The spring member is clad with different metals (aluminum on one side, copper on the other) at different locations to match the foil terminal materials. This local quality variation ensures that each contact interface uses compatible metals, eliminating galvanic corrosion while maintaining reliable electrical connection.
Solution Approach 2:
The spring member is constructed as a composite material with aluminum and copper cladding on opposite sides. This composite structure allows the single spring member to connect to both aluminum and copper foil terminals without causing galvanic corrosion, as each side contacts only its compatible metal.
2Reliability
If bolted pressure connections are used, then terminal connection is achieved, but open-circuiting occurs due to loose connections
Solution Approach 1:
The spring member is designed to be elastically deformable, allowing it to dynamically adapt to variations in terminal position and maintain consistent contact pressure. This dynamic capability prevents loose connections and open-circuiting while accommodating manufacturing tolerances and thermal expansion.
Solution Approach 2:
The spring member's elastic properties enable it to self-adjust and maintain optimal contact pressure without external fasteners or adjustment mechanisms. The spring automatically compensates for position variations and maintains secure connection, eliminating the need for bolts or clips.
3Reliability
If bolted pressure connections are used, then terminal connection is achieved, but short-circuiting occurs due to stray mounting hardware
Solution Approach 1:
The invention extracts and eliminates the need for separate mounting hardware (bolts, nuts, clips) by integrating the connection function into a single spring member. This removal of extraneous components eliminates sources of short-circuiting while simplifying the overall connection structure.
Solution Approach 2:
The spring member combines multiple functions into a single component: electrical conduction, mechanical connection, and contact pressure maintenance. This merging eliminates the need for separate mounting hardware that could cause short-circuits, while achieving all necessary connection functions.
4Reliability
If conventional pressure connections are used, then terminal connection is achieved, but current concentration occurs over small terminal area
Solution Approach 1:
The flexible spring member dynamically conforms to the terminal surface, maximizing the contact area between the spring and terminal. This dynamic adaptation ensures current is distributed over the largest possible area, reducing current density and improving connection reliability.
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
The solution provides a reliable, low-resistance electrical connection over a substantial terminal area, eliminating galvanic corrosion and allowing for easy cell replacement, while maintaining structural integrity and preventing loose connections.
Implementation Method 1
A conductive spring member having first and second end portions that are curved... The aluminum foil terminal is sandwiched between the conductive spring and the inner periphery of the pocket of the first retaining member, while the copper foil terminal is sandwiched between the conductive spring
Implementation Method 2
The spring member is clad with aluminum on one side and copper on the other, and the end portions are oppositely curved... so that the aluminum-clad side contacts the aluminum foil terminal within the pocket of the first retaining member, and the copper-clad side contacts the copper foil terminal
Data Source
Figure 1~3
Figure 2
Figure 4
AI summary
A pressure connection apparatus includes a conductive spring member (30) having first and second end portions (30b, 30a) that are curved, and first and second retaining members (32, 34) having curved pockets (36, 38) that are oppositely oriented for receiving the first and second curved ends (30b, 30a) of the conductive spring member (30). An aluminum foil terminal (12a) of one battery (10a) is sandwiched between the conductive spring (30) and the pocket (36) of the first retaining member (32), while a copper foil terminal (14c) of another battery (10c) is sandwiched between the conductive spring (30) and the pocket (38) of the second retaining member (34). The spring member (30) is clad with aluminum on one side and copper on the other, and the end portions (30b, 30a) are oppositely curved so that the aluminum-clad side contacts the aluminum foil terminal (12a) within the pocket (36) of the first retaining member (32), and the copper-clad side contacts the copper foil terminal (14c) within the pocket (38) of the second retaining member (34).