Zirconia-Coated Lithium Cathode Oxides for Longer Cycle Life
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Solution Overview
Problem
Existing cathode materials in lithium batteries, particularly those with high nickel content, suffer from rapid aging and performance loss due to electrochemical degradation mechanisms, leading to decreased capacity and cycle life.
Innovation Solution
A process involving the dry mixing of transition metal oxides or hydroxides with pyrogenically produced zirconium dioxide or mixed oxides containing zirconium, followed by heating to form a mixed lithium transition metal oxide with a homogeneous zirconium oxide distribution, enhancing the cathode material's stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional cathode materials with high nickel content are used, then energy density is improved, but cycling stability deteriorates due to rapid aging and electrochemical degradation
Solution Approach 1:
The patent uses composite materials by combining high-nickel cathode materials with coating layers of metal oxides (such as aluminum oxide, titanium oxide, zirconium oxide) or lithium-containing compounds. This composite structure allows the high energy density of nickel-based materials while the coating layer provides protection against degradation, resolving the contradiction between energy density and cycling stability.
Solution Approach 2:
The patent applies parameter changes by modifying the surface composition and structure of the cathode material through coating with various metal oxides and lithium-containing compounds. These parameter changes at the surface level protect the bulk high-nickel material from degradation, enabling both high energy density and improved cycling stability.
2Reliability
If coating with metal oxides is applied to inhibit unwanted reactions, then long-life stability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-coating the cathode material particles with metal oxides or lithium-containing compounds before assembly into the battery. This pre-coating process protects the material from degradation from the start, improving long-life stability without requiring complex in-situ treatments during battery operation.
Solution Approach 2:
The patent uses thin coating layers of metal oxides that serve as sacrificial protective barriers. These coating layers are relatively simple to apply and, while they may degrade or consume over time, they protect the main cathode material effectively, providing a cost-effective solution to improve stability.
3Reliability
If surface coating is applied to prevent electrochemical degradation, then cycling performance is improved, but capacity loss during initial cycles increases
Solution Approach 1:
The patent applies local quality by coating only the surface of the cathode material particles with metal oxides or lithium-containing compounds. This localized treatment protects the surface from degradation and unwanted reactions without significantly affecting the bulk capacity of the high-nickel cathode material, thus improving cycling performance with minimal capacity loss.
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 resulting modified mixed lithium transition metal oxide exhibits improved cycling stability and performance, with a homogeneous distribution of zirconium oxide particles that effectively inhibits unwanted reactions and enhances the long-life stability of lithium batteries.
Implementation Method 1
a transition metal oxide, and/or a transition metal hydroxide and/or a transition metal oxyhydroxide and pyrogenically produced zirconium dioxide and/or a pyrogenically produced mixed oxide comprising zirconium are subjected to dry mixing
Implementation Method 2
the coated precursor compound and the lithium containing compound are heated to obtain the mixed lithium transition metal oxide
Implementation Method 3
pyrogenically produced zirconium dioxide and/or a pyrogenically produced mixed oxide comprising zirconium
Data Source
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AI summary
Process for producing a mixed lithium transition metal oxide usable as an active positive electrode material in lithium batteries, wherein i) a transition metal oxide, and/or a transition metal hydroxide and/or a transition metal oxyhydroxide and a pyrogenically produced zirconium dioxide and/or a pyrogenically produced mixed oxide comprising zirconium are subjected to dry mixing by means of an electric mixing unit to obtain a coated precursor compound, wherein the mixing unit has a specific electrical power of 0.05 - 1.5 kW per kg of the coated precursor compound; ii) the coated precursor compound is mixed with a lithium containing compound; and iii) the mixture of the coated precursor compound and the lithium containing compound is heated at a temperature between 500 and 1400 °C to obtain the mixed lithium transition metal oxide.