Positive Electrode Sheet Composition for Low-Gas High-Temperature Storage
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Solution Overview
Problem
Commercial lithium-manganese dioxide batteries exhibit poor electrochemical performance, including large weight loss, severe swelling, and increased internal resistance after high-temperature storage, failing to meet application requirements due to inadequate high-temperature storage stability.
Innovation Solution
A positive electrode sheet material using manganese dioxide with a specific surface area of 10 to 26 g/cm² as the positive active material, combined with a conductive agent having a specific surface area of 10 to 60 g/cm², and a binder, which suppresses secondary reactions and reduces gas generation, thereby improving high-temperature storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manganese dioxide with large specific surface area is used as positive active material, then electrochemical activity is improved, but high-temperature storage stability deteriorates due to increased catalytic activity causing side reactions and gas generation
Solution Approach 1:
The patent changes the physical parameter of specific surface area of manganese dioxide from conventional large values to a controlled range of 10-26 m²/g. This parameter modification reduces the catalytic activity of manganese dioxide at high temperatures, thereby suppressing side reactions between the electrolyte and manganese dioxide, reducing gas generation, and improving high-temperature storage stability while maintaining acceptable electrochemical performance
2Reliability
If conventional positive electrode materials are used, then manufacturing simplicity is maintained, but battery performance deteriorates after high-temperature storage with severe swelling and weight loss
Solution Approach 1:
The patent modifies the specific surface area parameter of manganese dioxide to 10-26 m²/g, which fundamentally changes the material's catalytic behavior at high temperatures. This parameter change prevents severe battery swelling and composition degradation during high-temperature storage, maintaining battery integrity and performance stability.
3Reliability
If high-temperature storage stability is improved by reducing manganese dioxide surface area, then electrochemical activity may be reduced, but the patent maintains acceptable performance through optimized surface area range
Solution Approach 1:
The patent optimizes the specific surface area parameter to a specific range of 10-26 m²/g rather than simply minimizing it. This optimized parameter range strikes a balance between reducing high-temperature catalytic activity (improving storage stability) and maintaining sufficient electrochemical activity for acceptable battery performance.
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 battery maintains original electrical performance and enhances high-temperature storage stability while maintaining high-current pulse performance, as evidenced by reduced swelling and weight loss, and minimal impact on discharge capacity.
Implementation Method 1
The specific surface area of the positive active material manganese dioxide is low, so that its catalytic activity in high-temperature storage is low, side reactions in an electrolyte can be suppressed
Data Source
AI summary
A positive electrode sheet material, a positive electrode sheet, and a battery are provided. The positive electrode sheet material includes a positive active material, a conductive agent, and a binder. The positive active material includes manganese dioxide having a specific surface area in a range of 10 g/cm2 to 26 g/cm2. The conductive agent includes a first conductive agent having a specific surface area in a range of 10 g/cm2 to 60 g/cm2.