Lithium Manganese Nickel Composite Cathode for High Capacity Batteries

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Solution Overview

Problem

Lithium titanium oxide-based lithium secondary batteries face limitations in capacity and power due to insufficient energy density and structural deformation during charge/discharge, necessitating an improvement in cathode active materials to enhance performance and safety.

Innovation Solution

A cathode active material comprising a combination of lithium manganese composite oxide with a spinel structure and lithium nickel composite oxide, maintaining high voltage and exhibiting superior lifespan and power, is developed, along with the use of lithium titanium oxide as an anode active material to maintain safety and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lithium titanium oxide is used as an anode active material, then safety and stability are improved, but capacity and power are insufficient

Engineering Contradiction:
Improvesafety and stabilityVSAvoidcapacity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent uses a composite cathode material consisting of lithium manganese composite oxide with spinel structure and lithium nickel composite oxide. This composite structure combines the safety and stability benefits of lithium titanium oxide anode with high-capacity cathode materials, achieving both reliability and capacity requirements.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If conventional carbon-based anode materials are used, then capacity is improved, but safety and stability deteriorate due to dendrite generation

Engineering Contradiction:
ImprovecapacityVSAvoidsafety and stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent extracts the problematic dendrite-forming carbon-based anode material and replaces it with lithium titanium oxide, which provides superior safety and stability. The capacity requirement is then met through the optimized cathode composite material rather than the anode.

Inventive Principle:
Principle #2Taking out (Extraction)

3Quantity of substance

If lithium manganese composite oxide with spinel structure is combined with lithium nickel composite oxide, then capacity and power are enhanced, but device complexity increases

Engineering Contradiction:
ImprovecapacityVSAvoidcathode material composition
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent optimizes the compositional parameters of the cathode materials, specifically controlling the ratios of lithium manganese composite oxide and lithium nickel composite oxide, as well as the doping elements and their concentrations. This parameter optimization achieves high capacity and power while managing the complexity through defined compositional ranges.

Inventive Principle:
Principle #35Parameter changes

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 combination of lithium manganese and nickel composite oxides in the cathode active material significantly enhances the capacity and power of lithium secondary batteries while maintaining safety and stability, outperforming conventional materials in terms of energy density and cycle life.

Implementation Method 1

a cathode active material comprising a combination of lithium manganese composite oxide with a spinel structure represented by the following Formula 1 with lithium nickel composite oxide represented by the following Formula 2

Methodology Applied
Scientific EffectElectrochemical reaction: Redox Reactions

Implementation Method 2

Lithium secondary batteries as power sources of electric vehicles (EVs) and hybrid electric vehicles (HEVs)

Methodology Applied
Scientific EffectIon diffusion: Diffusion

Data Source

PatentUS9111662B2Cathode active material and lithium secondary battery comprising the same
Publication Date: 2015.08.18 LG ENERGY SOLUTION LTD

AI summary

Disclosed is cathode active material comprising a combination of a lithium manganese composite oxide having a spinel structure represented by the following Formula 1 with a lithium nickel composite oxide represented by the following Formula 2, the cathode active material having a broad potential region at 3.0 to 4.8V upon initial charge:LixMyMn2−yO4−zAz  (1)wherein 0.9≦x≦1.2, 0<y<2, and 0≦z<0.2;M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti and Bi; andA is at least one monovalent or bivalent anion, andLi1+y′Niz′M″1−z″O2−z″A′z″  (2)wherein 0≦y′≦0.1, 0<z′≦0.5, and 0≦z″<0.2;M″ is at least one selected from the group consisting of elements stable for 6-coordination, including Mn, Co, Mg and Al; andA′ is at least one monovalent or bivalent anion.Disclosed is also a secondary battery comprising the cathode active material.