Battery Pack Copper Plate Welding Structure
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Solution Overview
Problem
The existing battery pack manufacturing process is complex and costly due to multiple welding steps, leading to increased defect rates and low weldability between nickel plates and aluminum terminals, and there is a need for a compact, high-power, and large-capacity battery pack with simplified manufacturing.
Innovation Solution
A battery pack design featuring a battery cell array with pouch-shaped cells arranged laterally, directly connected to a protection circuit module (PCM) via resistance welding using conductive plates that surround the cathode terminals, reducing the number of welding steps and enhancing weldability, and allowing for series or parallel connections based on device requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel plates are connected to aluminum terminals using resistance welding, then electrical connection is achieved, but welding coupling force is low and weldability is poor due to lower resistance of aluminum terminal
Solution Approach 1:
A copper plate is introduced as an intermediary component between the nickel plate of the PCM and the aluminum terminal of the battery cell. The copper plate serves as a mediator that facilitates better electrical and mechanical connection, overcoming the poor weldability between nickel and aluminum directly. The copper plate is welded to both the nickel plate and aluminum terminal, creating a reliable three-component connection structure.
2Ease of manufacture
If battery cells are connected in series or parallel using nickel plates and then connected to PCM, then electrical connection is achieved, but manufacturing process becomes complex and costs increase
Solution Approach 1:
The invention merges the functions of series/parallel connection and PCM connection into a single integrated structure. The copper plate serves dual purposes: it connects the battery cell terminal to the PCM while also enabling series or parallel connection between multiple battery cells. This eliminates the need for separate nickel plates for cell-to-cell connection, simplifying the manufacturing process and reducing structural complexity.
Solution Approach 2:
The copper plate is designed to perform multiple functions simultaneously: it acts as an electrical connector between the battery cell and PCM, serves as a series or parallel connection element between multiple cells, and provides mechanical support. This multi-functionality reduces the number of components needed and simplifies the overall battery pack structure.
3Reliability
If multiple welding steps are used to connect battery cells and PCM, then reliable electrical connection is achieved, but defect rate increases and manufacturing efficiency decreases
Solution Approach 1:
The invention combines multiple welding operations into a single integrated welding process. The copper plate is welded to both the nickel plate and aluminum terminal in one setup, eliminating the need for separate welding steps. This reduces the total number of welding operations, decreases defect rates, and improves manufacturing efficiency while maintaining reliable electrical connection.
4Power
If conventional battery pack structure is used, then manufacturing is straightforward, but the battery pack size is large and power density is low
Solution Approach 1:
The invention merges the connection functions into a compact integrated structure using the copper plate, which reduces the overall space required for connections and components. This allows for a more compact battery pack design with higher power density, suitable for applications like laptops where space is limited.
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 simplifies the manufacturing process, reduces costs, and achieves high weldability and a compact structure for battery packs, enabling the production of high-power and large-capacity packs suitable for various devices, including laptops, with improved safety and reliability.
Implementation Method 1
electrical connection regions between cathode terminals of the battery cells and the protection circuit module are configured to have a structure in which conductive plates attached to the tops of the respective connection terminals of the protection circuit module are welded
Data Source
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AI summary
Disclosed herein is a battery pack including (a) a battery cell array comprising two or more battery cells, each of which has an electrode assembly of a cathode/separator/anode structure disposed in a battery case together with an electrolyte in a sealed state, arranged in the lateral direction, (b) a protection circuit module (PCM) including connection terminals connected to electrode terminals of the battery cells by resistance welding, metal plates to electrically connect the battery cells to each other, and a protection circuit to control an operation of the battery pack, the PCM being connected to the upper end of the battery cell array, and (c) a pack case in which the battery cell array and the protection circuit module are disposed, wherein electrical connection regions between cathode terminals of the battery cells and the protection circuit module are configured to have a structure in which conductive plates attached to the tops of the respective connection terminals of the protection circuit module are welded so that the conductive plates surround the respective cathode terminals of the battery cells.