Lithium Manganese Oxide Cathode Conductive Coating for 3V Region
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Solution Overview
Problem
Conventional lithium manganese oxide cathode active materials exhibit poor charge-discharge properties and cycle life in the 3V region due to phase transition and low electrical conductivity, limiting their practical application in secondary batteries.
Innovation Solution
Applying a conductive material to the surface of lithium manganese oxide particles with a spinel structure, enhancing electrical conductivity and reducing reactions with the electrolyte, thereby improving charge-discharge properties and cycle life in both the 3V and 4V regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If spinel lithium manganese oxide is used in the 3V region, then thermal safety and low cost are achieved, but real capacity is lower than theoretical capacity due to phase transition
Solution Approach 1:
The patent optimizes the phase composition parameters to achieve a balance between capacity and stability. By controlling the tetragonal phase content to 10-50% and maintaining the cubic phase as dominant, the material achieves both high real capacity (approaching theoretical capacity) and phase stability during charge-discharge cycles in the 3V region
2Power
If conventional lithium manganese oxide is used, then thermal safety and low cost are achieved, but electrical conductivity is low limiting charge-discharge performance
Solution Approach 1:
The patent combines spinel lithium manganese oxide with conductive carbon materials to create a composite cathode structure. The carbon component provides enhanced electrical conductivity while the lithium manganese oxide maintains its thermal safety and cost advantages, resulting in improved overall charge-discharge performance
3Reliability
If cobalt is used in large quantities in cathode active materials, then excellent cycle life properties and charge-discharge efficiency are achieved, but cost increases and resource availability becomes limited
Solution Approach 1:
The patent replaces expensive cobalt with cheaper manganese-based materials (spinel lithium manganese oxide). While pure manganese oxide has limitations, the patent overcomes these through phase composition control and carbon composite formation, achieving acceptable cycle life properties at lower cost and with better resource availability
Solution Approach 2:
The patent modifies the chemical composition parameters by reducing or eliminating cobalt content and using manganese-rich spinel structure instead. This substitution, combined with phase control and carbon composite formation, achieves a cost-effective alternative that maintains adequate cycle life properties
4Quantity of substance
If nickel-based cathode active materials are used, then high discharge capacity and relatively low cost are achieved, but rapid phase transition occurs and safety reduces when exposed to air and moisture
Solution Approach 1:
The patent replaces nickel-based materials with manganese-based spinel lithium manganese oxide, which offers comparable cost advantages and maintains good discharge capacity while providing superior thermal stability and safety, particularly in the 3V region where nickel materials struggle
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 application of a conductive material increases the real capacity of lithium manganese oxide cathode active materials to theoretical levels, significantly improving charge-discharge performance and cycle life in the 3V region, overcoming limitations of phase transition and electrolyte interactions.
Implementation Method 1
a conductive material is applied to the surface of lithium manganese oxide particles as a coated material, so as to exhibit favorable charge-discharge properties
Implementation Method 2
the above oxide is present in a single cubic phase in the 4V region due to phase transition based on Jahn-Teller distortion, while being converted into two-phase comprising the cubic phase and the tetragonal phase in the 3V region
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Disclosed herein is a cathode active material including a lithium manganese oxide, in which the lithium manganese oxide has a spinel structure with a predetermined constitutional composition represented by Formula 1 described in the detailed description, wherein a conductive material is applied to the surface of lithium manganese oxide particles, so as to exhibit charge-discharge properties in the range of 2.5 to 3.5V as well as in the 4V region.