Zirconium-Modified Lithium Cobalt Oxide Cathode for Battery Safety
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Solution Overview
Problem
Lithium ion secondary batteries using lithium cobalt composite oxide face challenges with cycle characteristics, low-temperature heavy load performance, and safety, particularly when zirconium is added as a coarse or micro powder, which compromises capacitance and safety.
Innovation Solution
A cathode active material is developed by mixing zirconium-containing lithium cobalt composite oxide with lithium cobalt composite oxide, where zirconium is incorporated within specific composition and particle size ranges to enhance capacitance, cycle stability, and safety, and the battery is constructed with a non-aqueous electrolyte and optimized electrode structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If zirconium is added as coarse or micro powder to lithium cobalt composite oxide, then high capacitance is achieved, but safety deteriorates remarkably
Solution Approach 1:
The patent changes the particle size parameter of zirconium-containing lithium cobalt composite oxide to a specific range (10-30 μm arithmetic mean diameter) to achieve high capacitance while maintaining safety. This parameter optimization resolves the contradiction by finding the optimal particle size that balances capacitance enhancement with safety requirements.
Solution Approach 2:
The patent creates a composite material system by mixing zirconium-containing lithium cobalt composite oxide with conventional lithium cobalt composite oxide in a specific weight ratio (95:5 to 50:50). This composite approach allows the benefits of zirconium addition (high capacitance) while mitigating its negative effects (safety deterioration) through proper composition control.
2Ease of operation
If zirconium is added to lithium cobalt composite oxide, then low-temperature output characteristics are improved, but cycle characteristics deteriorate
Solution Approach 1:
The patent optimizes the particle size parameter of zirconium-containing lithium cobalt composite oxide (10-30 μm arithmetic mean diameter) to simultaneously improve low-temperature output characteristics and maintain good cycle characteristics. This parameter control prevents the deterioration of cycle life while achieving better low-temperature performance.
Solution Approach 2:
The patent forms a composite material by combining zirconium-containing lithium cobalt composite oxide with conventional lithium cobalt composite oxide in controlled proportions. This composite structure allows the zirconium component to enhance low-temperature performance while the conventional component maintains cycle stability, resolving the contradiction between these two performance aspects.
3Quantity of substance
If lithium cobalt composite oxide is used to achieve high voltage and high energy density, then battery capacitance increases, but voltage drop at large-output discharge at low temperature increases
Solution Approach 1:
The patent creates a composite cathode material by mixing zirconium-containing lithium cobalt composite oxide with conventional lithium cobalt composite oxide. The zirconium-containing component improves low-temperature discharge characteristics by reducing voltage drop, while the conventional component maintains the high voltage and energy density properties, thus resolving the contradiction between energy density and low-temperature 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 solution improves the battery's high capacitance, cycle characteristics, and low-temperature heavy load performance while ensuring safety, by using zirconium-containing lithium cobalt composite oxide in combination with lithium cobalt composite oxide within defined composition and particle size limits.
Implementation Method 1
a cathode active material in which a first composite oxide and a second composite oxide are mixed, the first composite oxide being a zirconium-containing lithium cobalt composite oxide containing zirconium Zr as a sub-component element in a lithium cobalt composite oxide
Data Source
AI summary
A cathode with a cathode active material is provided. The cathode active material is obtained by mixing a zirconium-containing lithium cobalt composite oxide containing zirconium as a sub-component element in a first lithium cobalt composite oxide expressed by a formula LitCoMsO2 (where M is at least one kind of element selected from Fe, V, Cr, Ti, Mg, Al, B, and Ca; 0≦s≦0.03; 0.05≦t≦1.15), and a second lithium cobalt composite oxide expressed by a formula LixCol-yAyO2 (where A is at least one kind of element selected from Mg and Al; 0.05≦x≦1.15; 0≦y≦0.03).