Li2MnO3 Anode Composite Material for High-Capacity Lithium Batteries
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Solution Overview
Problem
Current lithium secondary battery anode materials for electric cars and power storage systems face limitations in achieving high energy density and safety, with traditional materials like LMO, NMC, and olivine-type LiFePO4 having insufficient energy density and safety concerns, which restricts the driving distance and commercialization of medium- and large-size batteries.
Innovation Solution
Development of an Li2MnO3-based anode composite material using a method involving coprecipitation, followed by sintering at specific temperatures, to create a material with high capacity and energy density, specifically Li(LixNiyCozMnwO2+α), which is then used to manufacture electrodes and charge/discharge in a controlled voltage range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional LMO, NMC or olivine-based anode materials are used, then the battery has acceptable safety, but the energy density is limited to about 120 to 150 mAh/g which is insufficient for high driving distance
Solution Approach 1:
The patent uses Li2MnO3 as a composite anode material that combines the safety benefits of manganese-based materials with high capacity characteristics. The material achieves both safety and high energy density (200-460 mAh/g) by utilizing the unique electrochemical properties of Li2MnO3, particularly its ability to deliver high capacity at elevated voltages above 3.7V
Solution Approach 2:
The patent changes the operating voltage parameter to above 3.7V to fully exploit the high capacity of Li2MnO3. By operating at elevated voltages, the material achieves its full potential capacity range of 200-460 mAh/g, significantly higher than traditional materials operated at conventional voltage ranges
2Quantity of substance
If nickel-based materials like LiNiO2 are used to achieve excellent capacity, then the energy density improves, but safety becomes problematic
Solution Approach 1:
The patent uses Li2MnO3 as an intermediary material that provides the safety benefits associated with manganese-based compounds while delivering high capacity similar to nickel-based materials. The material acts as a safe alternative to nickel-based materials by achieving comparable performance through different chemical mechanisms
3Reliability
If iron phosphate materials are used to achieve excellent safety and high capacity, then the discharge voltage is limited to about 3.0 V which restricts energy density
Solution Approach 1:
The patent changes the voltage parameter by operating Li2MnO3 at elevated voltages above 3.7V, in contrast to iron phosphate materials that are limited to about 3.0V. This parameter change enables the anode material to achieve higher energy density while maintaining safety characteristics
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 Li2MnO3-based anode composite material achieves a high initial capacity of 200 to 240 mAh/g and exhibits superior charge and discharge properties, particularly when heat-treated at 850°C, enhancing the electrochemical performance and life of lithium secondary batteries.
Implementation Method 1
preparing a precursor of an Li2MnO3-based anode composite material Li(LixNiyCozMnwO2+α) using coprecipitation by mixing a complexing agent with a starting material solution
Implementation Method 2
subjecting mixed powder to a first sintering; and subjecting the first-sintered powder to a second sintering
Data Source
AI summary
This disclosure synthesizes an anodic composite material Li(LixNiyCozMnwO2+α) of Li2MnO3 series whose theoretical capacity is a level of about 460 mAh/g, and to produce an electrode of a high capacity using the synthesized anodic composite material. Also provided is a method for charging and discharging the electrode. Here, the method for producing an anodic composite material for a lithium secondary battery includes the steps of: mixing a nickel nitrate solution, a manganese nitrate solution, and a cobalt nitrate solution to produce a starting material solution; and mixing the starting material solution with a complexing agent so as to produce an anodic composite material Li(LixNiyCozMnwO2+α) of Li2MnO3 series by means of coprecipitation.