Lead-Acid Battery Grid Structure Against Corrosion Growth
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Solution Overview
Problem
Liquid-type lead storage batteries used in vehicles with idling stop systems experience premature failure due to corrosion-induced growth of the positive electrode grid body, leading to internal short circuits and reduced discharge capacity, particularly when subjected to deep discharge and frequent charge/discharge cycles.
Innovation Solution
The battery design incorporates a positive electrode current collector with a laterally long grid substrate featuring thick lateral intermediate bones and controlled diagonal vertical intermediate bones, along with a specific angle and cross-sectional area ratio, to enhance mechanical strength and prevent deformation and peeling of the positive electrode mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the positive electrode grid body is made thinner to reduce weight, then the weight decreases, but the mechanical strength decreases leading to easier corrosion-induced growth and deformation
Solution Approach 1:
The grid substrate employs varying bone thicknesses at different locations: lateral intermediate bones have a first thickness while longitudinal intermediate bones have a second thickness different from the first. This local variation in thickness provides enhanced mechanical strength where needed (lateral direction for corrosion resistance) while maintaining overall weight efficiency.
Solution Approach 2:
The grid substrate uses a composite structure combining different bone configurations (lateral and longitudinal intermediate bones with different thicknesses) and materials (lead or lead alloy) to achieve optimal balance between mechanical strength, corrosion resistance, and weight.
2Reliability
If the lateral intermediate bones are made thicker to prevent corrosion-induced growth, then the corrosion resistance improves, but the manufacturing complexity increases
Solution Approach 1:
The grid substrate is segmented into distinct functional components: frame bones, lateral intermediate bones with first thickness, and longitudinal intermediate bones with second thickness. This segmentation allows each component to be optimized independently for its specific function while maintaining overall structural integrity.
Solution Approach 2:
Different regions of the grid substrate have different bone thicknesses tailored to local requirements: lateral intermediate bones are thicker to resist corrosion-induced growth in the lateral direction, while longitudinal intermediate bones have different thickness to balance structural needs. This localized optimization improves corrosion resistance without uniformly increasing complexity.
Data Source
AI summary
A liquid-type lead storage battery includes a positive electrode collector formed of a lead alloy having a rolled structure. A grid substrate of the collector has an upper frame bone located on the upper side and a lower frame bone located on the lower side, each extending laterally, and a pair of vertical frame bones extending vertically. A lug projects upward from a position shifted to the side close to either one of the pair of vertical frame bones from the longitudinal center of the upper frame bone. The intermediate bones have vertical intermediate bones from the upper to lower frame bone and lateral intermediate bones connecting the pair of vertical frame bones. At least one of the lateral intermediate bones has a cross-sectional area B larger than an average value A of the cross-sectional areas of the plurality of lateral intermediate bones, such that B/A is 1.15 or more.