Composite Cathode Material for High-Compaction Li-Ion Cells
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Solution Overview
Problem
High-nickel cathode materials for energy storage devices are prone to breakage under high compaction density, limiting their use in high energy density batteries due to their bulk density and particle fragility, and existing lithium cobalt oxide materials are toxic, costly, and resource-limited.
Innovation Solution
A cathode material composed of first and second lithium-containing transition metal oxide particles with specific diameter ratios and surface areas, coated with boron and other elements, which are mixed to enhance structural stability and reduce side reactions, allowing for high energy density and long cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-nickel cathode materials are used to reduce cobalt content and increase specific capacity, then cost and cobalt resource dependency are reduced, but particle breakage occurs under high compaction density
Solution Approach 1:
The patent uses composite materials by coating high-nickel cathode particles with a dual-layer structure: an inner layer of lithium nickel aluminum oxygen compound and an outer layer of lithium nickel cobalt manganese oxide compound. This composite structure reinforces the particle strength while maintaining low cobalt content, preventing breakage under high compaction density.
2Quantity of substance
If high-nickel cathode materials are used to achieve higher energy density, then specific capacity increases, but structural stability deteriorates due to particle breakage
Solution Approach 1:
The patent applies beforehand cushioning by pre-coating the high-nickel cathode particles with a protective dual-layer coating before electrode fabrication. This protective layer acts as a cushion that absorbs mechanical stress during compaction and cycling, preventing structural degradation and maintaining stability throughout the battery's service life.
3Stability of the object's composition
If lithium cobalt oxide is used as cathode material to ensure structural stability, then reliability is maintained, but cost increases and resource availability decreases
Solution Approach 1:
The patent applies local quality by concentrating cobalt only in the outer protective layer (lithium nickel cobalt manganese oxide) rather than throughout the entire particle structure. The inner core uses cobalt-free or low-cobalt lithium nickel aluminum oxygen compound, achieving resource efficiency while maintaining structural stability through the cobalt-containing outer layer.
Data Source
AI summary
A cathode material includes: a plurality of first particles. Each first particle includes a secondary particle composed of a plurality of third particles, and the first particle includes a first lithium-containing transition metal oxide; and a plurality of second particles. The second particle includes a fourth particle and/or a secondary particle composed of a plurality of fourth particles, and the second particle includes a second lithium-containing transition metal oxide. The electrochemical device including the cathode material is significantly improved in the aspects of energy density, capacity attenuation and service life.