Carbon-Coated Li6CoO4 Cathode Additive for Low-Gas Fast Charging
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Solution Overview
Problem
Lithium secondary batteries face limitations in achieving high charge/discharge capacity, safety due to gas generation, and low electrical conductivity of positive electrode additives, which affect battery stability and performance.
Innovation Solution
A positive electrode additive comprising lithium cobalt oxide with a carbon material adsorbed on its surface, specifically selected elements like W, Cu, and functional groups, improving electrical conductivity and reducing gas generation, is used to enhance the battery's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional irreversible additives like Li6CoO4 are used to achieve high charge/discharge capacity, then capacity is improved, but structural instability occurs causing gas generation and electrode volume expansion
Solution Approach 1:
The patent applies composite materials by combining Li6CoO4 particles with carbon materials (graphite, carbon nanotubes, or carbon nanofibers) to form a composite additive. The carbon material forms a coating on the surface of Li6CoO4 particles, creating a stable structure that prevents gas generation while maintaining high charge/discharge capacity. This composite approach resolves the contradiction by providing both the high capacity of Li6CoO4 and the structural stability of carbon materials.
2Quantity of substance
If conventional irreversible additives are used to achieve high capacity, then capacity is improved, but electrical conductivity remains very low (10−11 S/cm or less)
Solution Approach 1:
The patent uses composite materials by forming a composite of Li6CoO4 and carbon materials. The carbon material component provides high electrical conductivity while Li6CoO4 provides high capacity. The composite structure allows electrons to move efficiently through the conductive carbon network, resolving the contradiction between high capacity and low electrical conductivity.
Solution Approach 2:
The carbon material acts as an intermediary substance that bridges the electrical conductivity gap. It forms a conductive network around Li6CoO4 particles, facilitating electron transport without interfering with the electrochemical reactions of Li6CoO4. This intermediary carbon layer enables high electrical conductivity while preserving the high capacity characteristics.
3Quantity of substance
If conventional irreversible additives are used to achieve high capacity, then capacity is improved, but gas generation occurs causing volume expansion and safety issues
Solution Approach 1:
The patent converts the harmful gas-generating properties of Li6CoO4 into a beneficial stable structure by coating it with carbon material. The carbon coating prevents direct exposure of Li6CoO4 to electrolyte, blocking the gas generation pathway while allowing lithium ion transport. This transforms the harmful gas evolution into a stable, safe composite structure that maintains high 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 improves the electrical performance and safety of lithium secondary batteries by increasing charge/discharge capacity and reducing gas generation, maintaining high capacity retention and efficient fast charging capabilities.
Implementation Method 1
a carbon material adsorbed on a surface of the lithium cobalt oxide
Data Source
AI summary
The present technology relates to a positive electrode additive for a lithium secondary battery and a positive electrode for a lithium secondary battery including the same, wherein the positive electrode additive contains a carbon material on a surface of a lithium cobalt oxide represented by Chemical Formula 1 to improve the low electrical conductivity of the positive electrode additive, and an effect of improving the problem caused by the amount of gases generated during initial charging and discharging (i.e., “activation”) is excellent, and thus a positive electrode and lithium secondary battery including the positive electrode additive have excellent electrical performance.