Lithium Cobalt Composite Oxide Coating for Battery Gas Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-aqueous electrolyte batteries using lithium titanium composite oxide as a negative electrode face issues with electrolyte solution decomposition and gas generation due to the high lithium absorption/desorption potential, leading to battery expansion and reduced cycle stability.
Innovation Solution
A non-aqueous electrolyte battery design featuring a negative electrode with a lithium absorption/desorption potential of 0.4 V or more and a positive electrode with a layered lithium nickel cobalt manganese composite oxide and lithium cobalt composite oxide, where the latter's surface is coated with a metal compound, maintaining a specific pore volume and surface area to suppress electrolyte decomposition and gas generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium titanium composite oxide is used as negative electrode active material, then high energy density is achieved, but electrolyte solution decomposition and gas generation occur due to high lithium absorption/desorption potential
Solution Approach 1:
A protective coating layer comprising metal fluoride, metal oxide, or metal carbonate is applied to the surface of the lithium titanium composite oxide particles. This coating acts as an intermediary barrier that prevents direct contact between the high-potential lithium titanium composite oxide and the electrolyte solution, thereby suppressing electrolyte decomposition and gas generation while maintaining the high energy density benefits of the lithium titanium composite oxide negative electrode.
2Use of energy by moving object
If lithium titanium composite oxide is used as negative electrode active material, then high energy density is achieved, but outer case expansion occurs due to gas generation
Solution Approach 1:
The protective coating layer serves as a mediator that eliminates the root cause of outer case expansion by preventing electrolyte decomposition and gas generation at the lithium titanium composite oxide surface, thereby maintaining battery shape stability while preserving high energy density.
Solution Approach 2:
The protective coating is applied in advance to the lithium titanium composite oxide particles before electrode assembly. This preliminary protective action prevents electrolyte decomposition and gas generation from occurring in the first place, thereby preventing outer case expansion before it can happen during battery operation.
3Reliability
If lithium titanium composite oxide is used as negative electrode active material, then high lithium absorption/desorption potential is achieved, but cycle stability deteriorates due to electrolyte solution decomposition
Solution Approach 1:
The protective coating layer comprising metal fluoride, metal oxide, or metal carbonate acts as a stable intermediary barrier that prevents direct interaction between the high-potential lithium titanium composite oxide and the electrolyte solution. This eliminates the decomposition reactions that would otherwise occur at the electrode-electrolyte interface, thereby maintaining cycle stability while preserving the high lithium absorption/desorption potential necessary for reliable 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 achieves stable cycle performance, maintains high energy density, and prevents outer case expansion by controlling gas generation, thereby enhancing the battery's overall capacity and longevity.
Implementation Method 1
a negative electrode housed in the outer case and comprising a current collector and a negative electrode layer formed on at least one of surfaces of the current collector; wherein the negative electrode layer comprises an active material having a lithium absorption/desorption potential of 0.4 V vs. Li/Li+
Implementation Method 2
wherein at least surface of the lithium cobalt composite oxide is coated with a metal compound
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present invention provides a non-aqueous electrolyte battery which is excellent in cycle property and is prevented from expansion of an outer case owing to suppression of gas generation. A non-aqueous electrolyte battery of the present invention includes an outer case, a negative electrode housed in the outer case and comprising a current collector and a negative electrode layer formed on at least one of surfaces of the current collector, a positive electrode housed in the outer case and comprising a current collector and a positive electrode layer formed on at least one of surfaces of the current collector and opposed to the negative electrode layer, and a non-aqueous electrolyte filled in the outer case, wherein the negative electrode layer includes an active material having a lithium absorption/desorption potential of 0.4 V vs. Li/Li+ or more, the positive electrode layer includes an active material containing a layered lithium nickel cobalt manganese composite oxide and a lithium cobalt composite oxide in which at least a part of a surface thereof is coated with a metal compound, the positive electrode layer has a pore volume with a pore diameter of 0.01 µm or more and 1.0 µm or less obtained by the mercury press-in method, the pore volume being 0.06 mL or more and 0.25 mL or less per 1 g of a weight of the positive electrode layer, and a pore surface area within the pore volume range is 2.4 m2/g or more and 8 m2/g or less.