Amorphous Carbon-Coated Graphite Anode for Faster Battery Charging
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Solution Overview
Problem
Secondary batteries have long charging times, which limits the rapid popularization of new energy vehicles due to user anxiety over mileage and affects the actual experience, necessitating an improvement in fast charging performance.
Innovation Solution
A negative electrode active material is developed, comprising artificial graphite with an amorphous carbon coating layer, where the particle size uniformity is controlled between 0.25 and 0.45, enhancing energy density, charging speed, and cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If secondary batteries use conventional electrode materials and structures, then they achieve stable energy storage, but they suffer from long charging times that limit rapid popularization of new energy vehicles
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the inner core (natural graphite) and outer shell (artificial graphite) have different properties optimized for different functions. The natural graphite core provides high capacity while the artificial graphite shell enables fast charging kinetics, resolving the contradiction between energy density and charging speed at the local material level.
Solution Approach 2:
The patent uses composite materials by combining natural graphite and artificial graphite into a core-shell composite structure. This composite approach allows the battery to simultaneously achieve the high energy density of natural graphite and the fast charging capability of artificial graphite, directly addressing the charging time limitation.
2Quantity of substance
If secondary batteries increase energy density to improve mileage, then user anxiety over mileage is reduced, but charging time increases further affecting user experience
Solution Approach 1:
The patent segments the electrode material into two distinct components: natural graphite for energy storage capacity and artificial graphite for fast charging performance. This segmentation allows each component to optimize its function independently, achieving high energy density without sacrificing charging speed.
Solution Approach 2:
By creating a composite electrode material combining natural and artificial graphite in a core-shell structure, the patent achieves both high energy density (from natural graphite) and fast charging capability (from artificial graphite), resolving the trade-off between quantity of energy stored and time to charge.
3Reliability
If secondary batteries use traditional electrode structures to ensure stability, then cycle life is maintained, but fast charging performance is compromised
Solution Approach 1:
The patent applies local quality by assigning different functional roles to different parts of the electrode material. The artificial graphite shell provides structural stability and fast ion transport channels for reliability, while the natural graphite core provides high capacity, achieving both cycle life and fast charging performance through spatial differentiation of material properties.
Solution Approach 2:
The artificial graphite shell acts as an intermediary between the electrolyte and the natural graphite core. It facilitates fast ion transport to the core while maintaining structural integrity, enabling both fast charging performance and long cycle life by mediating the interaction between the electrolyte and the high-capacity core material.
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 secondary battery using this active material achieves higher energy density, faster charging, longer cycle life, and improved high-temperature storage performance, addressing the limitations of existing batteries.
Implementation Method 1
coating the artificial graphite with an organic carbon source, performing heat treatment to form an amorphous carbon coating layer on at least a part of the surface of the artificial graphite
Data Source
AI summary
The present application discloses a negative electrode active material and a method for preparing the same, a secondary battery, and an apparatus including the secondary battery. The negative electrode active material includes a core and a coating layer covering the surface of the core, the core includes artificial graphite, the coating layer includes amorphous carbon, and the particle size uniformity of the negative electrode active material is from 0.25 to 0.45.