Composite Cathode Material for Lithium Secondary Battery Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium titanium oxide-based lithium secondary batteries face limitations in capacity and power due to insufficient theoretical capacity compared to conventional carbon-based anode materials, necessitating improvements in performance.
Innovation Solution
A cathode active material combining lithium manganese composite oxide with a spinel structure and lithium nickel composite oxide, maintaining high voltage during charge and discharge, and utilizing lithium titanium oxide as an anode active material to enhance battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium titanium oxide is used as an anode active material, then safety and stability are improved, but capacity is insufficient
Solution Approach 1:
The patent uses a composite cathode material consisting of lithium manganese composite oxide with spinel structure (LixMyMn2-yO4-z) and lithium nickel composite oxide (Li1+yNizM1-zO2-zA). This composite structure combines the safety and stability benefits of lithium titanium oxide anode with enhanced capacity from the dual-component cathode, resolving the capacity limitation while maintaining reliability.
Solution Approach 2:
The patent optimizes specific parameters including the spinel structure composition (controlling y and z values), particle size distribution (D50 of 2-30 μm), and mix ratio of the two cathode materials (50:50 to 99:1 by weight). These parameter changes enable the cathode to deliver broad potential region (3.0-4.8V) and high capacity while maintaining structural stability for long lifespan.
2Quantity of substance
If conventional carbon-based anode materials are used, then capacity is improved, but safety and stability deteriorate
Solution Approach 1:
The patent introduces lithium titanium oxide as an intermediary anode material that mediates between the high capacity needs and safety requirements. While lithium titanium oxide alone has limited capacity, when paired with the optimized composite cathode material, it provides a safe and stable platform that enables high capacity operation without the safety issues of conventional carbon-based anodes.
3Duration of action of moving object
If lithium manganese composite oxide with spinel structure is used, then power and lifespan are improved, but voltage maintenance during charge/discharge is challenged
Solution Approach 1:
The patent merges two cathode materials with complementary properties: lithium manganese composite oxide with spinel structure (providing broad potential region 3.0-4.8V and good lifespan) and lithium nickel composite oxide (providing high voltage and power). This combination allows the battery to maintain high voltage during charge/discharge while achieving superior lifespan and power simultaneously.
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 with lithium titanium oxide as an anode material results in batteries with superior lifespan, power, and capacity, overcoming the limitations of lithium titanium oxide alone.
Implementation Method 1
a cathode active material comprising a combination of lithium manganese composite oxide with a spinel structure... with lithium nickel composite oxide... maintaining high voltage during charge and discharge of batteries
Implementation Method 2
LixMyMn2−yO4−zAz... Li1+y′Niz′M′1−z′O2−z′′A′z′′... during charge and discharge of batteries
Data Source
AI summary
Disclosed is a cathode active material (and secondary battery comprising the same) 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, 0.5<z′≦0.9, 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.