Lithium Transition Metal Oxide with Tungsten and Boron for High-Rate Battery Stability
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Solution Overview
Problem
High-rate charge-discharge cycles in secondary batteries using lithium transition metal oxides as positive electrode active materials lead to structural deterioration, increased resistance, and decreased input characteristics due to volume changes and side reactions with the electrolyte.
Innovation Solution
Incorporating tungsten (W) and boron (B) into the positive electrode active material, with boron present both inside and on the surfaces of secondary particles formed by aggregating primary particles of lithium transition metal oxide, to stabilize the structure and suppress side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-rate charge-discharge cycles are performed, then power output is improved, but structural deterioration and resistance increase occur
Solution Approach 1:
The patent changes the chemical composition parameters of the positive electrode active material by incorporating tungsten (W) at 0.01-5 mol% and boron (B) at 0.01-5 mol% into the lithium transition metal oxide structure. These compositional parameter changes stabilize the crystal structure during high-rate charge-discharge cycles, preventing structural deterioration and maintaining input characteristics while enabling improved power output.
Solution Approach 2:
The patent creates a composite material system by combining lithium transition metal oxide with tungsten and boron elements. This composite structure, where W and B are incorporated into the oxide lattice, provides enhanced structural stability and resistance to degradation during high-rate cycling, allowing the material to maintain reliability while delivering improved power performance.
2Reliability
If W and B are added to lithium transition metal oxide, then input characteristics are maintained, but manufacturing complexity increases
Solution Approach 1:
The patent merges the functions of multiple additives into a single composite material system. Instead of applying separate coatings or treatments for structural stabilization and surface protection, the invention incorporates both tungsten and boron elements directly into the lithium transition metal oxide structure during synthesis, simplifying the manufacturing process while achieving multiple protective functions simultaneously.
Data Source
AI summary
A positive electrode active material for a secondary battery contains second particles which are produced by aggregation of primary particles of a lithium transition metal oxide containing Ni and W, and a boron compound present inside and on the surfaces of the secondary particles.