TM1-Substituted TM2 Oxide Nanocrystals for Stable Li-Ion Anodes
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Solution Overview
Problem
Traditional Li-ion battery electrodes face limitations in capacity due to intercalation reactions, and conversion and alloying reactions lead to mechanical issues like fracture and loss of electrical contact due to volume changes, along with low electronic conductivity in semiconductor or insulator materials.
Innovation Solution
Incorporating a transition metal-substituted binary transition metal oxide nanocrystals as anode active materials, specifically Cu-substituted Co3O4, which forms a dynamic, highly conductive framework that endures volume changes during lithiation/delithiation cycles, maintaining cycling stability and high capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conversion and alloying reactions are used to increase capacity, then electrode capacity is improved, but volume changes induce fracture and loss of electrical contact
Solution Approach 1:
The electrode material is segmented into nanoscale components (metallic nanoparticles dispersed in oxide matrix) to reduce the impact of volume changes and prevent fracture while maintaining high capacity
Solution Approach 2:
A composite material system is created combining metallic nanoparticles with metal oxide matrix, where the metal provides high capacity through conversion reactions and the oxide provides structural stability to accommodate volume changes
2Quantity of substance
If semiconductor or insulator materials are used for conversion reactions, then electrode capacity is improved, but electronic conductivity remains low
Solution Approach 1:
The composite combines metallic phases (high conductivity) with oxide phases (high capacity), creating a material that simultaneously achieves both high electronic conductivity and high electrode capacity
Solution Approach 2:
Different regions of the composite material have different properties: metallic regions provide high conductivity while oxide regions provide high capacity, allowing the material to exhibit both properties simultaneously at the microscale
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 anode active materials exhibit improved cyclic stability and higher capacities with reduced mechanical fractures and loss of contact, achieving high capacity retention and improved charge/discharge kinetics compared to conventional materials.
Implementation Method 1
In a lithiated state, the anode active material is characterized by a three-dimensional network of the TM1 and nanoparticles of Li2O and nanoparticles of the TM2... In a delithiated state, the anode active material is characterized by the network of the TM1 and nanoparticles of an oxide of the TM1 and nanoparticles of an oxide of the TM2
Data Source
AI summary
Provided is a Li+battery comprising an anode comprising an anode active material comprising a plurality of transition metal (TM1)-substituted binary transition metal (TM2) oxide nanocrystals, a cathode in electrical communication with the anode, a separator between the anode and the cathode, and an electrolyte in contact with the anode and the cathode. The anode active material, in a lithiated state, is characterized by a three-dimensional network of the TM1 and nanoparticles of Li2O and nanoparticles of the TM2, both types of nanoparticles distributed throughout the network. In a delithiated state, the anode active material is characterized by the network of the TM1 and nanoparticles of an oxide of the TM1 and nanoparticles of an oxide of the TM2, both types of nanoparticles distributed throughout the network. The TM1-substituted binary TM2 oxide may be characterized by a ratio of TM2/TM1 of at least about 5.