Graphite Anode Active Material for Cycle Swelling and Rapid Charging
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Solution Overview
Problem
Conventional secondary batteries using natural graphite as a negative electrode active material face issues with cycle swelling and rapid charging performance due to its mechanical strength and high temperature characteristics, which are exacerbated by the use of lithium metal, leading to reduced cycle life and energy density.
Innovation Solution
A negative electrode active material is developed by mixing spheroidized natural graphite with artificial graphite, optimizing particle size distribution and tap density to enhance cycle characteristics and rapid charging performance, while maintaining the advantages of both materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If natural graphite is used as negative electrode active material, then capacity is improved, but cycle swelling and high temperature characteristics deteriorate
Solution Approach 1:
The patent applies composite materials by mixing natural graphite particles with artificial graphite particles to create a negative electrode active material that combines the high capacity of natural graphite with the excellent cycle characteristics and low swelling of artificial graphite. The composite structure allows both materials to work synergistically, resolving the contradiction between capacity and cycle stability.
2Quantity of substance
If natural graphite is used as negative electrode active material, then capacity is improved, but rapid charging performance deteriorates
Solution Approach 1:
The composite material combines natural graphite's high capacity with artificial graphite's superior rapid charging performance. The artificial graphite component provides faster lithium ion insertion/extraction kinetics, while the natural graphite maintains high capacity, achieving both goals simultaneously.
3Quantity of substance
If lithium metal is used as negative electrode, then energy density is improved, but safety and cycle life deteriorate due to dendrite formation
Solution Approach 1:
The patent replaces the problematic lithium metal with carbon-based materials (natural and artificial graphite) that, while having slightly lower theoretical energy density, provide significantly improved safety and cycle life. The carbon materials act as a stable host structure that prevents dendrite formation while maintaining practical energy density through optimized particle composition.
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 use of a mixture of spheroidized natural graphite and artificial graphite improves cycle characteristics, swelling, and rapid charging performance, addressing the limitations of natural graphite and enhancing the overall performance of secondary batteries.
Implementation Method 1
a carbon-based compound capable of reversible intercalation and desorption of lithium ions while maintaining structural and electrical properties
Implementation Method 2
exhibits excellent electrode life due to very reversible charge/discharge behavior due to the uniaxial orientation of the graphite layer
Data Source
AI summary
An anode active material for a secondary battery that has improved cycle swelling properties and rapid charge performance, an anode comprising same, and a method for manufacturing same. The anode active material is a mixture of artificial graphite and spherical natural graphite, wherein the spherical natural graphite has an average particle diameter (D 50) of 12 μm or less, with D 90-D 10 value ranging from 5 μm to 12 μm.