Battery Intermediate Terminal Design for Welding Diversion
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Solution Overview
Problem
The existing methods for increasing battery output in secondary batteries, such as nickel-hydride and lithium-ion batteries, face issues with faulty welding due to the 'diverting phenomenon' during resistance welding of intermediate terminals, where electric current intended for one arm portion passes through the other, leading to suboptimal connections.
Innovation Solution
The design includes a roll-up unit with an intermediate terminal having a pair of arm portions resistance-welded to the exposed portion, a first connecting portion with a protruding shape and tapered face to facilitate easy insertion, and a second connecting portion that narrows the electric current path between welding points, preventing diverting phenomena and ensuring proper electrical continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of turns of the roll-up unit is increased to increase battery output, then the battery output is improved, but the thickness of the roll-up unit increases making it difficult to press the exposed portion into a sheet shape
Solution Approach 1:
The invention divides the terminal connection structure into multiple components: an intermediate terminal with arm portions that contact the exposed portion from inside the roll-up unit, and a collector terminal that contacts the exposed portion from outside. This segmentation allows the system to handle the electrical connection without requiring excessive compression of the exposed portion, thus resolving the contradiction between maintaining thin profile and achieving reliable welding.
2Reliability
If an intermediate terminal with arm portions is used for resistance welding, then electrical continuity is achieved, but the diverting phenomenon occurs where electric current intended for one arm portion passes through the other arm portion causing faulty welding
Solution Approach 1:
The invention introduces a collector terminal as an intermediary component that receives electrical current from the exposed portion externally and transfers it to the electrode terminal. This mediator approach allows the intermediate terminal's arm portions to make contact without requiring high current density at each contact point, thereby preventing the diverting phenomenon where current would incorrectly pass through the other arm portion, and ensuring reliable welding quality.
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 configuration effectively suppresses the diverting phenomenon, reducing the load on the exposed portion and preventing faulty welding, thereby enhancing the reliability of the electrical connections in the battery.
Implementation Method 1
an intermediate terminal placed inside the roll-up unit and having a pair of arm portions resistance-welded to the exposed portion
Implementation Method 2
a collector terminal placed outside the roll-up unit and resistance-welded to a position opposite to the arm portion in the exposed portion to provide electrical continuity
Data Source
AI summary
A battery includes a roll-up unit provided by winding a sheet unit around an axis, the sheet unit including an electrode sheet having an active material and a separator, the roll-up unit having an exposed portion on which the active material is not placed at an end of the electrode sheet in a direction of the axis; an outer case housing the roll-up unit and having an electrode terminal; an intermediate terminal inside the roll-up unit and having a pair of arm portions resistance-welded to the exposed portion, a first connecting portion connecting the arm portions, and a hole portion formed in the first connecting portion and located between welding points formed in the arm portions; and a collector terminal outside the roll-up unit and resistance-welded to a position opposite to the arm portion in the exposed portion to provide electrical continuity between the roll-up unit and the electrode terminal.