Mixed Cathode Active Material for Lithium Battery Capacity
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Solution Overview
Problem
Lithium secondary batteries face challenges in achieving high capacity and stable lifetime characteristics, particularly with composite dimensional manganese oxide (CDMO) cathode active materials, which are difficult to charge and discharge due to structural instability and limited lithium intercalation/deintercalation capabilities.
Innovation Solution
A cathode active material is developed by mixing lithium manganese oxide (xMnO2·(1-x)Li2MnO3) with a lithium-containing transition metal oxide (Li2Ni x Cu 1-x O2) to enhance reversible capacity and structural stability, along with the inclusion of conductive agents like graphite and carbon to improve conductivity and lithium ion participation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If composite dimensional manganese oxide (CDMO) is used as cathode active material to achieve high capacity, then the battery capacity increases, but the structural stability deteriorates leading to poor lifetime characteristics
Solution Approach 1:
The patent combines CDMO (xMnO2·(1-x)Li2MnO3) with LiCoO2 to form a composite cathode active material. This composite structure allows the CDMO to provide high capacity while LiCoO2 contributes structural stability, resolving the contradiction between high capacity and structural stability. The composite material leverages the advantages of both components to achieve improved lifetime characteristics.
2Use of energy by moving object
If CDMO is used as cathode active material to increase energy density, then the energy density improves, but the charge-discharge capability deteriorates due to limited lithium intercalation/deintercalation
Solution Approach 1:
The patent merges CDMO with LiCoO2 in a composite structure where LiCoO2 provides excellent lithium ion conductivity and charge-discharge capability. This combination allows the battery to maintain high energy density from CDMO while achieving good charge-discharge performance from LiCoO2, resolving the contradiction between energy density and charge-discharge capability.
3Quantity of substance
If LiCoO2 is used as cathode material to achieve high capacity, then the capacity increases, but the safety deteriorates due to oxygen discharge and structural degeneration at high temperature
Solution Approach 1:
The patent applies local quality by creating a composite structure where different materials serve different functions. CDMO provides high capacity in specific regions while LiCoO2 provides structural stability and safety in other regions. This spatial distribution of functional properties allows the battery to achieve high capacity while maintaining safety through the stabilizing effect of LiCoO2.
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 mixed cathode active material exhibits improved high capacity, extended lifetime, and a wide state of charge (SOC) range, suitable for electric vehicles and other applications, by ensuring sufficient lithium participation and minimizing dendrite formation.
Implementation Method 1
lithium secondary batteries having high energy density and discharge voltage... lithium ion intercalation/deintercalation
Implementation Method 2
charge and discharge are performed... difference between a charge capacity and a discharge capacity
Data Source
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AI summary
Provided are a cathode active material having high capacity and excellent lifetime characteristics as well as being inexpensive by mixing transition metal oxide having high irreversible capacity with composite dimensional manganese oxide (CDMO) of the following Chemical Formula 1, which has high capacity and good lifetime characteristics but is difficult to be charged and discharged by being used alone, and a lithium secondary battery including the cathode active material: [Chemical Formula 1] xMnO2·(1-x)Li2MnO3 (0<x<1).