Balanced Current Collectors for Battery Stacks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional battery configurations face challenges in achieving uniform current distribution across battery cells, particularly in larger batteries with extended dimensions, leading to inefficiencies in current flow and potential hot spots or dead zones.
Innovation Solution
The use of pack boards with specific circuit board configurations and current collectors that facilitate z-directional current transmission through the battery stack, combined with conductive vias and traces, and the integration of busbars to ensure balanced impedance and uniform current delivery across the battery cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional battery configurations are used with extended dimensions, then the battery can accommodate larger capacity, but current distribution becomes non-uniform leading to hot spots and dead zones
Solution Approach 1:
The battery pack is divided into multiple battery cells arranged in a stack, with each cell having its own current collector. The current collectors are segmented into multiple regions (first region, second region, third region) with different impedance characteristics, allowing current to be distributed uniformly across all cells by directing higher current through cells at the edges and lower current through central cells.
Solution Approach 2:
Different regions of the current collector are assigned different electrical impedance values. The first region (adjacent to power distribution block) has higher impedance, the second region has medium impedance, and the third region has lower impedance. This local variation in impedance ensures uniform current distribution across the battery stack, preventing hot spots and dead zones.
2Reliability
If current collectors with high impedance are used to control current flow, then current distribution can be balanced, but voltage drop and energy loss increase
Solution Approach 1:
The current collector is divided into regions with progressively decreasing impedance from the power distribution block outward. This gradient approach balances current distribution while minimizing overall voltage drop, as only the region closest to the power distribution block has high impedance, and this high impedance is localized rather than uniform across the entire collector.
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 approach enhances uniform current distribution across battery cells, reduces the overall footprint by allowing for recessed components, and improves battery operation by minimizing hot spots and dead zones, thereby optimizing performance and efficiency.
Implementation Method 1
A plurality of conductive vias may be defined through the second edge of the first circuit board and may electrically couple the second surface of the first circuit board with the first surface of the first circuit board
Implementation Method 2
A first conductive trace formed adjacent the proximal end may be characterized by a first impedance. A second conductive trace adjacent a distal end of the first edge of the first circuit board may be characterized by a second impedance less than the first conductive trace
Data Source
AI summary
Energy storage devices, battery cells, and batteries of the present technology may include a first circuit board characterized by a first surface and a second surface opposite the first surface. The second surface may include a conductive layer. The batteries may include a battery stack overlying the first circuit board and electrically coupled with the second surface of the first circuit board. The battery stack may include a plurality of battery cells. The batteries may include a second circuit board overlying the battery stack. The second circuit board may be characterized by a first surface and a second surface opposite the first surface. The second surface may include a conductive layer, and the battery stack may be electrically coupled with the second surface of the second circuit board. The batteries may include a power distribution block electrically coupled with the first and second circuit boards.