Lead-Acid Battery Negative Electrode for PSOC Life and Charge Acceptance
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Solution Overview
Problem
Lead-acid batteries face challenges in maintaining high life performance in partial state of charge (PSOC) cycles without compromising low-temperature high-rate performance and charge acceptance performance, due to the adverse effects of adding carbon black and lignin on the negative electrode material's specific surface area and adsorption.
Innovation Solution
A lead-acid battery design incorporating a negative electrode material with a combination of carbon materials having specific particle sizes and powder resistance ratios, along with a controlled amount of lignosulfonic acid or its salt as an organic expander, to maintain pore structure and conductive network integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of carbon black added to the negative electrode material is increased to improve PSOC life performance, then the PSOC life performance is improved, but the specific surface area of the negative electrode material decreases, causing deteriorated low-temperature high-rate performance
Solution Approach 1:
The invention uses a composite carbon material system comprising both graphite particles (3-50 μm) and carbon black particles (0.5-3 μm) in specific weight ratios. This composite structure combines the advantages of both materials: graphite provides structural stability and prevents excessive surface area reduction, while carbon black enhances conductivity and PSOC performance. The synergistic effect resolves the contradiction between improving PSOC life and maintaining specific surface area.
Solution Approach 2:
The invention optimizes the particle size parameters and weight ratio parameters of the carbon materials. By controlling the particle size distribution (graphite: 3-50 μm, carbon black: 0.5-3 μm) and weight ratio (graphite: 60-95 wt%, carbon black: 5-40 wt%), the invention achieves both improved PSOC life performance and maintained specific surface area, resolving the technical contradiction through precise parameter optimization.
2Reliability
If the amount of lignin is increased to suppress deteriorated low-temperature high-rate performance, then the low-temperature high-rate performance is improved, but the charge acceptance performance deteriorates
Solution Approach 1:
The invention optimizes the lignin content parameter within a specific range (0.03-0.8 mass%) to balance low-temperature high-rate performance and charge acceptance performance. This parameter optimization ensures sufficient low-temperature performance while preventing excessive charge acceptance deterioration, resolving the technical contradiction through controlled parameter adjustment.
Solution Approach 2:
The invention creates a composite negative electrode material system combining carbon materials (graphite and carbon black) with lignin in optimized ratios. This composite structure allows the carbon materials to provide structural framework and conductivity while lignin provides expansion control and low-temperature performance enhancement, resolving the contradiction between low-temperature performance and charge acceptance.
3Reliability
If a large amount of carbon black is added to improve PSOC life performance, then the PSOC life performance is improved, but the pore structure is compromised, causing deteriorated charge acceptance performance
Solution Approach 1:
The invention uses a composite carbon material system where graphite particles (3-50 μm) form a structural framework that maintains pore structure integrity, while carbon black particles (0.5-3 μm) fill interstices to enhance conductivity and PSOC performance. This composite approach improves PSOC life while preserving the necessary pore structure for charge acceptance.
Solution Approach 2:
The invention applies different carbon materials to different functional requirements: graphite provides structural support and pore maintenance in regions requiring structural integrity, while carbon black provides conductivity enhancement in regions requiring electrical performance. This local differentiation resolves the contradiction between PSOC life improvement and pore structure preservation.
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 PSOC life performance while preserving low-temperature high-rate and charge acceptance performance, even with a small amount of organic expander, by optimizing the powder resistance ratio and specific surface area of the carbon materials.
Implementation Method 1
the carbon material contains a first carbon material having a particle size of 32 μm or more, and a second carbon material having a particle size of less than 32 μm; wherein a ratio of powder resistance R2 of the second carbon material to powder resistance R1 of the first carbon material: R2/R1 is 15 or more and 155 or less
Implementation Method 2
lignin (lignosulfonic acid or a salt thereof) of the organic expander is adsorbed to carbon black, so that the addition of a large amount of carbon black causes a decreased specific surface area of the negative electrode material
Data Source
Figure 1
AI summary
A lead-acid battery includes: a negative electrode plate; a positive electrode plate; and an electrolyte solution. The negative electrode plate contains a negative electrode material containing a carbon material and an organic expander. The carbon material contains a first carbon material having a particle size of 32 µm or more, and a second carbon material having a particle size of less than 32 µm. A ratio of powder resistance R2 of the second carbon material to powder resistance R1 of the first carbon material: R2/R1 is 15 or more and 155 or less. The organic expander contains lignosulfonic acid or a salt thereof, and a content of the organic expander in the negative electrode material is 0.03 mass% or more and 0.8 mass% or less.