Nickel Cathode Lithium Carbonate Coating via CO2 and Water Vapor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming coatings on high energy dense oxide-based cathode materials for lithium rechargeable batteries require specialized equipment and high temperature conditions, leading to increased complexity and cost, while also resulting in interfacial resistance, capacity fade, and diminished rate-performance due to direct contact with electrolytes.
Innovation Solution
A method involving exposure of a nickel-based cathode material to gaseous carbon dioxide and water vapor at controlled temperature, pressure, and humidity to form a lithium carbonate coating, which acts as a buffer, reducing interfacial resistance and enhancing cycle life and rate performance without the need for multistep reactions or specialized equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If atomic layer deposition is used to form coatings on cathode materials, then coating quality and protection against degradation are improved, but equipment complexity and manufacturing cost increase
Solution Approach 1:
The cathode material itself serves as the source of lithium for coating formation. The lithium present in the cathode material migrates to the surface and reacts with CO2 and H2O to form the protective lithium carbonate coating, eliminating the need for external lithium sources or complex deposition equipment.
Solution Approach 2:
The invention changes the physical state parameters of the reactants from solid/liquid (in traditional methods) to gaseous phase. By using gaseous CO2 and H2O vapor, the process can be conducted in simple atmospheric conditions without requiring specialized vacuum or deposition equipment, while still achieving effective coating formation.
2Reliability
If atomic layer deposition is used to form coatings on cathode materials, then coating quality is improved, but manufacturing cost increases
Solution Approach 1:
The cathode material provides its own lithium for coating formation, eliminating the need for separate lithium sources and reducing material costs. The process uses readily available atmospheric CO2 and water vapor, avoiding expensive precursor materials required in traditional deposition methods.
Solution Approach 2:
The invention uses inexpensive, readily available materials (atmospheric CO2 and water vapor) instead of expensive specialized precursors. The simple atmospheric chamber setup replaces costly specialized deposition equipment, making the process economically viable for large-scale manufacturing.
3Productivity
If high temperature conditions are used in coating formation, then coating formation efficiency is improved, but energy consumption and process complexity increase
Solution Approach 1:
The invention changes the temperature parameter from high temperature (traditional methods) to ambient or mild temperature conditions. By using gaseous reactants and the self-service mechanism, effective coating formation occurs without thermal activation, dramatically reducing energy consumption while maintaining practical coating formation rates.
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 lithium carbonate coating effectively reduces interfacial resistance, increases cycle life, and improves rate performance of lithium rechargeable batteries, maintaining 85% or more of its discharge capacity after three cycles and offering a cost-effective alternative to existing methods.
Implementation Method 1
exposing a nickel-based cathode material comprising a 1:2 molar ratio of lithium and oxygen to gaseous carbon dioxide and water vapor; and incubating the nickel-based cathode material and the carbon dioxide for a predetermined amount of time, wherein lithium carbonate is formed as a layer on an exterior surface of the cathode material
Data Source
AI summary
A method for producing a lithium carbonate coated cathode including convertible lithium by growing lithium carbonate onto its surface by exposure to carbon dioxide. An electrochemical cell comprising a lithium carbonate coated cathode having an exterior lithium carbonate coating with thickness in the range of about 2 nanometers to about 1 micron.