Boron-Doped Lithium-Rich Cathode Stabilizes Cycle Life
Solution Overview
Problem
Lithium-rich manganese-based cathode materials for lithium-ion batteries suffer from short cycle life due to spinel phase transition, particle fragmentation, and surface corrosion, limiting their commercial applications despite high specific energy capacity.
Innovation Solution
Boron-doping of lithium-rich manganese-based materials stabilizes their structure, improving performance over extended charging-discharging cycles through methods like co-precipitation and sol-gel synthesis, enhancing reversible capacity and tap density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium-rich manganese-based cathode materials are used to achieve high specific energy capacity, then energy density is improved, but cycle life deteriorates due to spinel phase transition, particle fragmentation, and surface corrosion
Solution Approach 1:
The patent applies parameter changes by doping boron elements into the lithium-rich manganese-based cathode material at controlled concentrations (0.01-0.10 mol ratio). This chemical parameter modification stabilizes the crystal structure, prevents spinel phase transition, and significantly improves cycle life while maintaining high specific energy capacity above 250 mAh/g
Solution Approach 2:
The patent creates a composite doped material structure where boron elements are incorporated into the Li2MnO3-LiMO2 composite framework. This composite approach combines the high capacity characteristics of lithium-rich materials with the structural stability provided by boron doping, achieving both high energy density and extended cycle life
2Ease of manufacture
If conventional preparation methods are used for lithium-rich materials, then manufacturing simplicity is maintained, but structural stability deteriorates leading to rapid capacity decay
Solution Approach 1:
The patent modifies preparation parameters by introducing boron-containing compounds during the synthesis process using established methods like co-precipitation or solid-state reaction. This parameter adjustment maintains manufacturing simplicity while dramatically improving structural stability and preventing particle fragmentation during cycling
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
Boron-doped lithium-rich manganese-based cathode materials demonstrate improved capacity retention and increased tap density, with reversible capacity exceeding 290 mA h/g after 80 cycles and maintaining over 200 mA h/g after 250 cycles, significantly extending battery life.
Implementation Method 1
Boron-doped lithium rich manganese based materials are developed for the cathodes of Li-ion batteries. The structure of Li-rich material is stabilized by boron doping
Implementation Method 2
The presently disclosed boron-doped lithium rich cathode materials can be prepared by the following methods: (2) Sol-gel method
Data Source
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AI summary
The present application discloses boron-doped lithium rich manganese based materials for cathodes of lithium ion batteries. The disclosed cathode materials can be prepared by co-precipitation and sol-gel methods. The chemical formula of this cathode material is Li[LiaMnbCocNidBx]O2 (a+b+c+d+x=1, a, b, x>0, c ≥ 0, d ≥ 0, c+d > 0). Lithium ion batteries using these cathode materials show impressive improvements in performance and increased tap density at low level of boron doping. The co-precipitation method is particularly suitable for large-scale industrial production. The sol-gel method is simple and can produce fine and uniform particles.