Lead Acid Battery Antimony Alloy Grid Corrosion
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Solution Overview
Problem
Lead acid batteries used in vehicles with stop-and-go and regenerative-braking systems face reduced service life due to frequent charge/discharge cycles at low state of charge (SOC), leading to electrolyte depletion and corrosion of negative electrode grids.
Innovation Solution
The battery design includes negative electrode plates with a Sb content of 0.0001 to 0.003 parts by weight in the active material layer and a positive electrode grid with a lead alloy layer containing 0.01 to 0.2 parts by weight of Sb, along with a Pb-alloy for the grids and connecting members, and a glass fiber or synthetic fiber separator to enhance chargeability and prevent corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a lead acid battery is used in vehicles with stop-and-go and regenerative-braking systems, then the battery can provide power during idle stops and store regenerative energy, but the service life is reduced due to frequent charge/discharge cycles at low SOC
Solution Approach 1:
The patent applies local quality by forming a lead alloy layer containing Sb (0.01 to 0.2 parts by weight per 100 parts by weight of positive electrode active material) specifically on the surface of the positive electrode grid where it contacts the active material. This localized Sb enrichment improves chargeability and suppresses deterioration during frequent charge/discharge cycles at low SOC, thereby extending service life while maintaining adaptability to stop-and-go and regenerative-braking systems
Solution Approach 2:
The patent uses composite materials by creating a Pb-alloy layer containing Sn and Sb on the positive electrode grid surface. This composite structure combines the benefits of Pb (base metal), Sn (improves chargeability), and Sb (suppresses passivation layer formation), resulting in enhanced performance under frequent charge/discharge conditions while extending battery service life
2Reliability
If the SOC is maintained at 90 to 100% for conventional engine starting batteries, then the battery remains charged for starting, but the battery cannot accommodate frequent charge/discharge cycles at lower SOC in stop-and-go and regenerative-braking systems
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition of the positive electrode grid surface through the addition of Sb (0.01 to 0.2 parts by weight per 100 parts by weight of positive electrode active material). This compositional change enables the battery to reliably maintain chargeability and suppress deterioration even when operating at lower SOC ranges (50 to 90%) required for stop-and-go and regenerative-braking systems
3Duration of action of stationary object
If a lead alloy layer containing Sn and Sb is formed on the positive electrode grid, then chargeability is improved and service life is extended, but the manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by forming the lead alloy layer containing Sb (0.01 to 0.2 parts by weight per 100 parts by weight of positive electrode active material) only on the surface of the positive electrode grid where it contacts the active material, rather than throughout the entire grid structure. This localized approach improves chargeability and extends service life while minimizing additional manufacturing complexity compared to bulk alloying
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 configuration extends the service life and reliability of the battery by improving chargeability, reducing electrolyte loss, and suppressing corrosion of the negative electrode grid, even under over-discharge conditions.
Implementation Method 1
a part of Sb which exists on a surface of the positive electrode grid dissolves in an electrolyte
Implementation Method 2
deposits on a negative electrode plate
Implementation Method 3
The deposited Sb on a negative electrode active material raises a charging potential of the negative electrode plate
Data Source
AI summary
A lead acid battery of the present invention has: an electrode plate pack including a plurality of negative electrode plates which each comprise a negative electrode grid having a tab and a negative electrode active material layer retained by the negative electrode grid, a plurality of positive electrode plates which each comprise a positive electrode grid having a tab and a positive electrode active material layer retained by the positive electrode grid, and a plurality of separators separating the positive and negative electrode plates; a positive electrode connecting member connected to each positive electrode plate of the electrode plate pack; and a negative electrode connecting member connected to each negative electrode plate of the electrode plate pack. The positive electrode grid has a lead alloy layer including 0.01 to 0.2 parts by weight of Sb per 100 parts by weight of the positive electrode active material on at least a part of the surface thereof where the positive electrode active material layer is in contact. The negative electrode active material layer includes 0.0001 to 0.003 parts by weight of Sb per 100 parts by weight of the negative electrode active material.