Dual-Layer Battery Cell Interconnects for Low-Resistance Current Collection
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Solution Overview
Problem
Conventional interconnect members in energy storage devices, particularly those using lithium ion batteries, suffer from high shunt current resistance, poor electrical contact, and susceptibility to damage due to high current flow, leading to power loss, cell imbalance, and increased maintenance costs.
Innovation Solution
The design incorporates interconnect members with slits or apertures aligned with energy storage cell terminals, using two independent metallic layers for each interconnect member, allowing for efficient current collection and voltage sensing, and utilizing materials like copper and nickel for optimal conductivity and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If interconnecting plates made of steel with high thermal and electrical conductivity are used, then electrical connectivity is improved, but resistance to high shunt currents and susceptibility to damage worsens
Solution Approach 1:
The interconnecting structure uses a composite design combining copper and nickel layers. The copper layer provides high electrical conductivity for low resistance connections, while the nickel layer offers high strength and resistance to high shunt currents. This composite material approach resolves the contradiction by integrating the beneficial properties of both materials in a single interconnecting structure.
2Ease of manufacture
If spot welding method with contact points is used to connect interconnecting plates to energy storage cells, then manufacturing simplicity is improved, but electrical contact quality and reliability worsen due to high resistance at contact points
Solution Approach 1:
The interconnecting plate is segmented into multiple functional layers (copper layer and nickel layer) with distinct roles. The copper layer is optimized for electrical conductivity and contact quality, while the nickel layer provides mechanical strength. This segmentation allows each layer to be optimized for its specific function, improving overall electrical contact quality while maintaining manufacturing feasibility through standardized layering processes.
3Device complexity
If conventional single-layer interconnecting structure is used, then device complexity is reduced, but power loss increases due to high resistance
Solution Approach 1:
The dual-layer composite structure combines copper's superior electrical conductivity with nickel's mechanical properties. The copper layer specifically addresses power loss by providing low-resistance current paths, while the nickel layer maintains structural integrity. Although the structure is more complex than a single layer, the modular layered design keeps manufacturing complexity manageable while delivering significant power loss reduction.
4Adaptability or versatility
If nickel material is used for energy storage cell terminals, then compatibility with dissimilar materials is improved, but electrical conductivity worsens compared to steel
Solution Approach 1:
The copper layer acts as an intermediary between the nickel terminal and the steel interconnecting plate. The copper layer provides excellent electrical conductivity and is compatible with nickel, creating an effective electrical bridge. This intermediary layer resolves the conductivity issue while maintaining material compatibility across the dissimilar material interface.
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 minimizes power loss, reduces cell imbalance, and enhances the reliability of energy storage devices by providing stable electrical connections and effective voltage monitoring, thereby improving the overall performance and reducing maintenance needs.
Implementation Method 1
the interconnecting plates including metal plates having high thermal and electrical conductivity are electrically connected to at least one terminal of each of the energy storage cells through a spot welding method having at least one contact point
Data Source
AI summary
An energy storage device includes: a cell holder assembly; energy storage cells disposed in the cell holder assembly; and interconnect members that connect with the energy storage cells. The interconnect members include: double row interconnecting structures disposed on opposite sides of the cell holder assembly; and a pair of single row terminal interconnecting structures that border the double row interconnecting structures on both sides. Each of the interconnect members includes a first independent metallic layer member and a second independent metallic layer member that are electrically coupled to each other and that electrically connect to the energy storage cells. The first independent metallic layer member is an upper member of each interconnect member that connects the interconnect member with a battery management system (BMS). The second independent metallic layer member is a lower member of each interconnect member that connects the interconnect member with the energy storage cells.