Bipolar Lead-Acid Collector Plate Sizing for Corrosion-Life Balance
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Solution Overview
Problem
Bipolar lead-acid storage batteries face challenges in maintaining long-term life performance and high capacity due to corrosion of the positive electrode current collector plate, which can lead to short circuits and reduced battery life, especially in power storage systems where cost and efficiency are critical.
Innovation Solution
A bipolar lead-acid storage battery design featuring a positive electrode current collector plate made from a lead alloy with a mass loss of 100 mg/cm² or less in sulfuric acid, and a thickness between 0.10 mm and 0.50 mm, optimized to achieve a volume-to-rated capacity ratio between 0.11 and 0.67, reducing corrosion and enhancing durability without significant cost increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the positive electrode current collector plate is made thinner to reduce material cost and improve capacity, then the volume-to-rated capacity ratio decreases and cost is reduced, but the plate becomes more susceptible to corrosion and may lead to short circuits
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness of the positive electrode current collector plate to a specific range (0.10 mm to 0.50 mm) and controlling the volume-to-rated capacity ratio (A/B) between 0.11 and 0.67. These parameter optimizations allow the battery to achieve both reduced material usage and sufficient corrosion resistance, resolving the contradiction between quantity reduction and reliability maintenance.
2Ease of manufacture
If the calcium content in the lead alloy is increased to improve hardening and handling properties, then the alloy hardens rapidly and is easier to handle, but PbCa precipitates form that increase corrosion and grid growth in high temperature applications
Solution Approach 1:
The patent applies parameter changes by precisely controlling the calcium content ratio in the lead alloy to be 0.005 mass % or more and less than 0.020 mass %. This optimized parameter range enables the alloy to achieve adequate hardening and handling properties while preventing excessive PbCa precipitate formation that would cause corrosion and grid growth, thus resolving the contradiction between ease of manufacture and corrosion resistance.
Solution Approach 2:
The patent applies local quality by creating a controlled distribution of alloying elements within the lead alloy, where calcium and tin are present in specific proportions to achieve local precipitation characteristics that balance hardening with corrosion resistance. This localized compositional control allows different regions of the alloy to exhibit properties that collectively resolve the manufacturing versus corrosion contradiction.
3Object-affected harmful factors
If the tin content in the lead alloy is increased to improve corrosion resistance, then the alloy achieves better corrosion protection, but the alloy becomes softer and more difficult to handle and requires special treatment for thin current collector plates
Solution Approach 1:
The patent applies parameter changes by optimizing the tin content ratio in the lead alloy to be 1.0 mass % or more and less than 2.0 mass %. This specific parameter range provides sufficient corrosion resistance while maintaining adequate hardness and handling properties, eliminating the need for special treatment processes and resolving the contradiction between corrosion resistance and ease of manufacture.
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
The optimized battery design achieves both long-term operation life and high capacity performance while maintaining cost-effectiveness, suppressing corrosion and ensuring reliable operation in power storage systems.
Implementation Method 1
a mass loss per total surface area of a test piece of 100 mg/cm² or less when measured after the test piece of the lead alloy sheet is placed in sulfuric acid
Implementation Method 2
bipolar lead-acid storage battery having a plurality of cell members each including a positive electrode including a positive electrode current collector plate and a positive active material layer, a negative electrode including a negative electrode current collector plate and a negative active material layer
Data Source
AI summary
A bipolar lead-acid storage battery has both life performance to withstand long-term operation and high capacity performance. Positive electrode current collector plates include a lead alloy sheet, a mass loss per total surface area of a test piece is 100 mg/cm2 or less when measured after the test piece is placed in sulfuric acid at a concentration of 38 mass % maintained at a temperature of 60° C., and a continuous anodization performed at a constant potential of 1,350 mV on a reference electrode for 28 days. A thickness of the collector plate arranged on one surface of a substrate that covers both a side of a positive electrode and a side of a negative electrode of a cell member is between 0.10 mm and 0.50 mm, and a ratio of a volume of the current collector plate to a rated capacity of the battery is between 0.11 and 0.67.