LiCo1-yMyO2+x Positive Active Material for Lithium Battery
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in achieving high capacity and cycle-life characteristics, with existing positive active materials not fully optimizing electrochemical performance.
Innovation Solution
A rechargeable lithium battery using a positive active material represented by Chemical Formula LiCo1-yMyO2+x, where 0.2 ≤ x ≤ 0.2 and 0 < y ≤ 0.3, incorporating Ni and at least one metal from Mn, B, Mg, Ca, Sr, Ba, Ti, V, Cr, Fe, Cu, and Al, with a method involving a dry synthesis process including heat-treatment and coating to enhance electrochemical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional positive active materials are used, then manufacturing simplicity is maintained, but charge and discharge efficiency remains low
Solution Approach 1:
The patent employs composite materials by combining multiple metal elements (Ni, Mn, B, Mg, Ca, Sr, Ba, Ti, V, Cr, Fe, Cu, Al) with cobalt in specific ratios to create a multi-element positive active material with the formula LiCo1-yMyO2+x. This composite approach achieves superior charge and discharge efficiency (86-94%) compared to conventional single-element materials, while the systematic composition design manages the complexity through defined manufacturing parameters.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the compositional parameters (x and y in the formula LiCo1-yMyO2+x) and manufacturing parameters (heat treatment temperature, coating thickness, sintering conditions) to optimize electrochemical performance. By adjusting these parameters within specific ranges, the material achieves enhanced charge and discharge efficiency without requiring overly complex processing procedures.
2Duration of action of stationary object
If existing positive active materials are used, then process simplicity is maintained, but cycle-life characteristics are insufficient
Solution Approach 1:
The patent applies preliminary action through pre-coating the positive active material particles with a protective layer before final sintering. This preliminary coating step, performed at controlled thickness and composition, prepares the material surface to resist degradation during cycling, thereby extending cycle-life. The pre-treatment approach allows the complex protective functions to be integrated early in the process, simplifying subsequent manufacturing steps.
Solution Approach 2:
The patent implements beforehand cushioning by incorporating buffer elements (such as Al, Mg, or B in the M component) that provide structural cushioning and chemical buffering during battery cycling. These elements are positioned in the crystal lattice to absorb stress and prevent structural collapse during repeated lithium insertion/extraction, thereby extending cycle-life without requiring complex external protective mechanisms.
3Stability of the object's composition
If conventional materials are used, then manufacturing simplicity is maintained, but capacity and power stability deteriorate
Solution Approach 1:
The patent applies local quality by creating spatially differentiated regions within the positive active material particles, including a core-shell structure where the inner core contains the high-capacity LiCo1-yMyO2+x material and the outer shell provides structural stability and surface protection. This local differentiation allows different regions to perform specialized functions, maintaining power and capacity stability while the overall composition remains systematically controlled through defined manufacturing parameters.
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 solution significantly improves charge and discharge efficiency by 86% to 94% and extends cycle-life, maintaining high power and capacity stability.
Implementation Method 1
Rechargeable lithium batteries use materials that reversibly intercalate or deintercalate lithium ions during charge and discharge reactions
Implementation Method 2
a method involving a dry synthesis process including heat-treatment and coating to enhance electrochemical characteristics
Data Source
AI summary
A rechargeable lithium battery includes a non-aqueous electrolyte, a negative electrode including a silicon-based negative active material, and a positive active material including a compound represented by a Chemical Formula 1, LiCo1-yMyO2+x, wherein, -0.2 ≤ x ≤ 0.2, 0 < y ≤ 0.25, and M includes Ni and at least one metal selected from Mn, B, Mg, Ca, Sr, Ba, Ti, V, Cr, Fe, Cu, and Al.