Nonaqueous Battery Electrode Impurity Control
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Solution Overview
Problem
The corrosion of metal foils in nonaqueous electrolyte batteries due to impurities from lithium manganese and nickel composite oxides, which can lead to gelation and degradation of the battery's performance.
Innovation Solution
A nonaqueous electrolyte battery design that incorporates a positive electrode active material layer with a lithium manganese composite oxide containing sulfate ions and a lithium nickel composite oxide with lithium hydroxide and a second alkaline compound, where the molar equivalent of sulfate ions is greater than lithium hydroxide but less than the second alkaline compound, to suppress gelation and corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lithium manganese composite oxide containing sulfate ions and lithium nickel composite oxide containing lithium hydroxide are used as positive electrode active materials, then the battery can be manufactured with conventional raw materials and processes, but the metal foil undergoes corrosion and the slurry undergoes gelation due to impurity reactions
Solution Approach 1:
The invention applies preliminary anti-action by introducing a corrosion inhibitor substance that proactively prevents the harmful reaction between sulfate ions and metal foil before corrosion can occur. The inhibitor is incorporated into the positive electrode structure in advance, creating a protective effect that counteracts the corrosive action of sulfate ions on the aluminum foil current collector.
Solution Approach 2:
The corrosion inhibitor substance acts as an intermediary between the sulfate ions and the metal foil. Instead of allowing direct harmful interaction between sulfate ions and aluminum foil, the inhibitor substance mediates this interaction, blocking the corrosive pathway while maintaining the functional properties of the battery components.
2Ease of manufacture
If sulfate ions and lithium hydroxide are present in the positive electrode active material, then conventional raw materials can be used, but gelation occurs during slurry preparation due to reactions between these impurities
Solution Approach 1:
The invention applies preliminary anti-action by incorporating a gelation prevention substance that proactively inhibits the gelation reaction between sulfate ions and lithium hydroxide during slurry preparation. This substance is built into the electrode structure in advance, preventing the harmful gelation that would otherwise occur when these impurities interact in the slurry.
Solution Approach 2:
The gelation prevention substance serves as an intermediary that blocks the direct interaction between sulfate ions and lithium hydroxide in the slurry. By mediating this interaction, the substance prevents the formation of gel structures that would impede slurry flow and electrode manufacturing processes.
Data Source
Figure 1
AI summary
A nonaqueous electrolyte battery includes a positive electrode active material layer containing a positive electrode active material. The positive electrode active material contains a lithium manganese composite oxide containing sulfate and/or sulfate ions, and a lithium nickel composite oxide containing lithium hydroxide and a second alkaline compound that is not lithium hydroxide, and, per unit mass of the positive electrode active material, the molar equivalent of the sulfate and/or the sulfate ions in the lithium manganese composite oxide is more than the molar equivalent of the lithium hydroxide in the lithium nickel composite oxide and less than the molar equivalent of the second alkaline compound in the lithium nickel composite oxide.