LiCoO2 Cathode Composition for High-Voltage Cycle Stability
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Solution Overview
Problem
Lithium cobaltate-based batteries face issues with irreversible phase transition at high charging voltages, leading to poor ion and electronic conductivity, capacity attenuation, and reduced cycle performance due to structural instability, which limits their energy density and stability.
Innovation Solution
A positive electrode material with the composition Lin-xNaxCo1-yMeyO2, where 0.7≤n≤1 and 0<x≤0.15, 0≤y≤0.15, and Me is selected from Al, Mg, Ti, Zr, Ni, Mn, Y, La, Sr, W, Sc, Ce, P, Nb, V, Ta, and Te, exhibiting specific X-ray diffraction patterns and peak intensity ratios that enhance structural stability and lithium ion deintercalation/intercalation, thereby improving capacity and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the charging voltage of lithium cobaltate is increased to improve energy density, then the energy density is improved, but irreversible phase transition occurs leading to poor ion and electronic conductivity
Solution Approach 1:
The patent applies parameter changes by precisely controlling the charging voltage range (3.0-4.5V) to avoid the critical threshold (≥4.55V) that triggers irreversible phase transition. This voltage parameter optimization maintains both high energy density and structural stability, preventing conductivity degradation while maximizing energy storage capacity.
Solution Approach 2:
The patent employs preliminary anti-action by pre-establishing protective measures through surface coating or modification of lithium cobaltate particles before charging. This preliminary treatment creates a protective barrier that prevents harmful phase transition at high voltages, thereby maintaining ion and electronic conductivity while enabling higher energy density operation.
2Stability of the object's composition
If the content of doped element in lithium cobaltate is increased to improve structural stability, then the structural stability is improved, but the gram capacity increases only slightly
Solution Approach 1:
The patent applies parameter changes by optimizing the doping element content within specific ranges rather than using excessive amounts. This controlled doping approach (with precise compositional parameters) achieves sufficient structural stability to prevent phase transition while minimizing the trade-off with gram capacity, thereby balancing both structural integrity and electrochemical performance.
Solution Approach 2:
The patent employs composite materials by combining lithium cobaltate with specifically selected doping elements in optimized ratios. This composite structure enhances structural stability through the dopant elements while preserving the electroactive sites of lithium cobaltate, achieving both improved stability and maintained gram capacity through synergistic material composition.
3Use of energy by moving object
If the charging voltage is increased to improve energy density, then the energy density is improved, but capacity attenuation occurs due to irreversible phase transition
Solution Approach 1:
The patent applies parameter changes by optimizing the charging voltage parameter to operate within the stable region (below 4.55V) where reversible phase transitions occur. This parameter optimization enables high energy density charging while preventing irreversible structural changes, thereby maintaining capacity and improving cycle performance over extended battery operation.
Solution Approach 2:
The patent employs beforehand cushioning by implementing protective surface treatments or coatings on lithium cobaltate particles prior to high-voltage charging. This preliminary protective layer acts as a cushion that absorbs mechanical stress and prevents irreversible phase transition during high-voltage operation, thereby preserving capacity and extending cycle life while enabling high energy density.
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 proposed positive electrode material demonstrates higher gram capacity and stable structure, enabling improved capacity and cycle performance in batteries, meeting the requirements for thin batteries by showcasing multiple charging and discharging platforms and enhanced electrochemical performance.
Implementation Method 1
according to the X-ray diffraction pattern of the positive electrode material, it can be seen that it has a peak 002 corresponding to a crystal plane 002, a peak 004 corresponding to a crystal plane 004, a peak 101 corresponding to a crystal plane 101
Data Source
AI summary
The present disclosure provides a positive electrode material, a battery and an electric device. A first aspect of the present disclosure provides a positive electrode material, the positive electrode material is Lin-xNaxCo1-yMeyO2, 0.7≤n≤1, 0<x≤0.15, 0≤y≤0.15, and Me is selected from one or more of Al, Mg, Ti, Zr, Ni, Mn, Y, La, Sr, W, Sc, Ce, P, Nb, V, Ta, and Te; a X-ray diffraction pattern of the positive electrode material includes a peak 002 corresponding to a crystal plane 002, a peak 004 corresponding to a crystal plane 004, a peak 101 corresponding to a crystal plane 101, a peak 102 corresponding to a crystal plane 102, and a peak 103 corresponding to a crystal plane 103; a peak intensity ratio of the peak 101 to the peak 004 is m, wherein m≥1.5.