Carbon Negative Electrode Material for Balanced Li-Ion Battery Performance
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Solution Overview
Problem
Current lithium-ion batteries face challenges in simultaneously improving energy density, cycle performance, and rate performance, with existing active materials failing to effectively enhance these metrics.
Innovation Solution
A negative active material with a carbon composition that satisfies specific graphitization degree and structural parameters, including a Gr/K ratio of 6 to 16, and a crystal size orientation, is used to optimize lithium ion insertion and extraction rates, thereby enhancing the battery's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional active materials are used, then manufacturing is simpler, but energy density and cycle performance cannot be simultaneously improved
Solution Approach 1:
The patent applies parameter changes by precisely controlling the graphitization degree of the carbon material within a specific range (0.85 to 0.95) and controlling the crystal size parameters (La/S ratio between 15-30, Lc/S between 1-3). These parameter optimizations enable simultaneous improvement of energy density and cycle performance while preventing lithium plating, resolving the contradiction between manufacturing simplicity and performance requirements.
2Productivity
If carbon material with high graphitization is used, then rate performance improves, but lithium plating occurs and cycle performance deteriorates
Solution Approach 1:
The patent resolves this contradiction by optimizing the graphitization degree to a specific range (0.85 to 0.95) rather than maximizing it. This controlled parameter change maintains high rate performance while preventing excessive graphitization that causes lithium plating and cycle degradation. The balanced parameter selection achieves both high productivity and reliability.
3Quantity of substance
If energy density is increased, then battery capacity improves, but cycle performance and rate performance deteriorate
Solution Approach 1:
The patent achieves simultaneous improvement of energy density and cycle performance through precise parameter control of the carbon material. By controlling the graphitization degree (0.85-0.95) and crystal size parameters (La/S ratio and Lc/S ratio), the invention enables higher energy density while maintaining excellent cycle performance and rate performance, breaking the traditional trade-off relationship.
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 optimized carbon material improves the energy density, cycle performance, and rate performance of lithium-ion batteries by balancing lithium ion insertion and extraction, reducing lithium plating, and maintaining high capacity retention rates.
Implementation Method 1
optimize lithium ion insertion and extraction rates
Implementation Method 2
Electrochemical devices (such as a lithium-ion battery) are widely used by virtue of advantages such as environmental friendliness, a high working voltage, a high specific capacity, and a long cycle life
Data Source
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AI summary
This application relates to a negative active material, an electrochemical device that uses same, and an electronic device. Specifically, this application provides a negative active material, including a carbon material. A ratio K between specific peak intensities of the carbon material, and a ratio of a graphitization degree Gr to K, are within specific ranges. The negative active material according to this application can significantly improve an energy density, cycle performance, and rate performance of the electrochemical device.