Lithium-Ion Cathode Carbon Coating via Transition Metal Bonds
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Solution Overview
Problem
Current nano-sized lithium-ion battery cathode materials have lower capacity and are prone to lattice interface damage due to their large specific surface area, leading to increased surface impedance and reduced lithium storage capabilities.
Innovation Solution
A transition metal-containing lithium-ion cathode material with a carbon coating that forms transition metal-X—C chemical bonds, where X is N, O, or S, to stabilize the carbon coating and repair the lattice interface, enhancing lithium storage capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If nano-sized cathode materials are used to improve rapid charge and discharge capacity, then the specific surface area increases, but the capacity decreases and lattice interface damage increases
Solution Approach 1:
The patent applies local quality by creating a non-uniform core-shell structure where the center region maintains the original cathode material composition for high lithium storage capacity, while the shell region contains transition metal compounds and carbon materials for surface stability and conductivity. This spatial differentiation allows the material to simultaneously achieve rapid charge/discharge performance from the conductive shell and high capacity from the high-capacity core.
Solution Approach 2:
The patent employs composite materials by combining multiple components within the cathode structure: the core cathode material (e.g., LiCoO2, LiMn2O4), transition metal compounds (e.g., Li2SiO3, Li2SiO2N), and carbon materials. This composite structure synergistically provides the high capacity of the core material while the shell components prevent interface damage and enhance electrical conductivity, resolving the contradiction between speed and capacity.
2Speed
If nano-sized cathode materials are used to improve rapid charge and discharge capacity, then the specific surface area increases, but surface impedance increases due to side reactions
Solution Approach 1:
The patent introduces transition metal compounds (such as Li2SiO3, Li2SiO2N, Li2SiO3F) as intermediary substances between the cathode material and the electrolyte. These intermediary layers act as protective barriers that prevent harmful side reactions at the surface, reducing the formation of insulating products like polycarbonates and high-molecular hydrocarbons. This mediation maintains low surface impedance while preserving the high surface area needed for rapid charge/discharge.
Solution Approach 2:
The patent changes the surface composition parameters by introducing transition metal compounds and carbon materials in the shell region. This parameter change modifies the surface chemistry to be more stable and less prone to side reactions, thereby reducing surface impedance. The controlled introduction of these components with specific properties (conductivity, stability) transforms the surface characteristics to resolve the impedance issue.
3Reliability
If carbon coating is applied to improve conductivity and reduce lattice interface damage, then electron transport accelerates, but the fundamental problem of lattice interface damage is not solved
Solution Approach 1:
The patent applies local quality by creating a non-uniform core-shell structure where the center region maintains the original cathode material composition for high lithium storage capacity, while the shell region contains transition metal compounds and carbon materials for surface stability and conductivity. This spatial differentiation allows the material to simultaneously achieve rapid charge/discharge performance from the conductive shell and high capacity from the high-capacity core.
Solution Approach 2:
The patent employs composite materials by combining multiple components within the cathode structure: the core cathode material (e.g., LiCoO2, LiMn2O4), transition metal compounds (e.g., Li2SiO3, Li2SiO2N), and carbon materials. This composite structure synergistically provides the high capacity of the core material while the shell components prevent interface damage and enhance electrical conductivity, resolving the contradiction between speed and capacity.
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 solution increases the gram capacity of the cathode material by adding lithium storage sites on the surface and within the channel, improving the material's ability to store lithium ions and maintain structural integrity during high charge and discharge rates.
Implementation Method 1
the transition metal on the surface of the lithium-ion cathode material coordinates with the carbon via X—C bonds to form transition metal-X—C chemical bonds
Implementation Method 2
The ultra-capacity lithium-ion battery cathode material of the present application is capable of interfacial lithium storage. That is, lithium ions can be stored at the surface of the ultra-capacity lithium ion cathode material containing the coating layer
Data Source
AI summary
A supercapacity lithium ion battery cathode material, a preparation method therefor and an application thereof. The supercapacity lithium ion battery cathode material consists of a transition metal-containing lithium ion cathode material and carbon which is coated on the surface of the lithium ion cathode material. The transition metal on the surface of the lithium ion cathode material is coordinated with carbon by means of X—C bonds to form transition metal-X—C chemical bonds, such that carbon stably coats the surface of the cathode material, wherein C is SP3 hybridization and/or SP2 hybridization, and X is at least one selected from among N, O and S. The supercapacity lithium ion battery cathode material connects the lithium ion cathode material and the carbon by means of the transition metal-X—C chemical bonds, and utilizes the transition metal-X—C chemical bonds to repair boundary of lattices on the surface of the cathode material, such that an interface between the lithium ion cathode material and a carbon layer can be optimized, to form an interface that can store Li, thereby increasing the per gram capacity of the cathode material, and laying the foundation for preparing a supercapacity lithium ion battery.