Bipolar Battery Separator Roughness for Uniform Active Material Use
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lead-acid storage batteries face issues with uneven active material usage leading to shortened lifespan and capacity reduction due to non-uniform surface pressure from separators, causing local softening and potential peeling of active material layers.
Innovation Solution
A bipolar storage battery design featuring cell members with positive and negative electrodes and separators with distinct surface roughness, where the surfaces in contact with active material layers have a finer surface roughness to ensure uniform pressure and usage, thereby extending battery life and maintaining capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional separators with uniform surface structure are used, then manufacturing is simple, but non-uniform surface pressure causes local softening and peeling of active material layers
Solution Approach 1:
The separator is designed with different surface structures at different locations: the first surface (contacting positive active material) has first surface structures, while the second surface (contacting negative active material) has second surface structures that differ from the first. This local differentiation allows each surface to be optimized for its specific contact requirements, preventing non-uniform pressure distribution and active material peeling while extending battery life.
2Reliability
If separators apply non-uniform pressure to active material layers, then assembly is easier, but active material peeling occurs and battery capacity reduces
Solution Approach 1:
The separator features differentiated surface structures where the first surface has first surface structures for contacting the positive active material layer and the second surface has second surface structures for contacting the negative active material layer. This local quality differentiation ensures uniform pressure distribution across both active material layers, preventing peeling and maintaining battery capacity without complicating the assembly process.
Data Source
AI summary
A bipolar storage battery includes cell members arranged with spacing in a stacked manner, each of the cell members including a positive electrode, a negative electrode, and separators interposed between the positive electrode and the negative electrode, space-forming members including a substrate that forms a plurality of spaces individually accommodating the plurality of cell members, and a frame body surrounding a side surface of the cell member. Each of the plurality of separators has a first surface and a second surface with different surface roughness, and a surface in contact with at least the positive active material layer is a surface having a smaller (finer) surface roughness than the first surface or the second surface. This configuration may suppress local use of active material during charging and discharging to achieve uniform use of active material in a cell.