Graphitized Carbon Anode Material for Better Battery Cycle Life
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Solution Overview
Problem
The cycle performance of lithium-ion batteries, used in electrochemical apparatuses, has not been adequately addressed by existing improvements to electrode active materials, failing to meet the increasing demands of performance and longevity.
Innovation Solution
A negative electrode active material is developed with a specific range of graphitization degree and controlled aspect ratio of carbon material particles, optimized for improved electrolyte infiltration and lithium ion deintercalation, enhancing cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the degree of graphitization of carbon material is increased, then the electrical conductivity and structural stability are improved, but the lithium ion diffusion rate decreases due to tighter layer structure
Solution Approach 1:
The patent optimizes the degree of graphitization parameter to a specific range (0.82-0.92) to achieve the best balance between structural stability and ion diffusion. This parameter optimization resolves the contradiction by finding the optimal point where both cycle performance and diffusion rate are satisfied.
2Quantity of substance
If particles with high aspect ratio are increased to improve capacity, then the specific capacity is enhanced, but the electrolyte infiltration and ion transport are hindered
Solution Approach 1:
The patent controls the aspect ratio distribution of carbon particles, limiting particles with aspect ratio >3.3 to less than 10% of total particles. This parameter control resolves the contradiction by preventing excessive aspect ratios that would block electrolyte infiltration while maintaining sufficient capacity.
Solution Approach 2:
The patent creates a distributed particle morphology where most particles have moderate aspect ratios suitable for electrolyte infiltration, while a small fraction of high aspect ratio particles contribute to capacity. This local quality differentiation resolves the contradiction between capacity and infiltration.
3Stability of the object's composition
If the carbon material is highly graphitized to improve stability, then the structural integrity is enhanced, but the deintercalation kinetics are slowed
Solution Approach 1:
The patent sets the degree of graphitization within the optimal range of 0.82-0.92, which provides sufficient structural stability while maintaining adequate deintercalation kinetics. This parameter optimization resolves the contradiction between stability and productivity.
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 negative electrode active material significantly improves cycle performance and extends the service life of lithium-ion batteries by ensuring balanced electrolyte infiltration and rapid lithium ion deintercalation.
Implementation Method 1
a degree of graphitization Gr of the carbon material that is measured in an X-ray diffraction analysis method is 0.82 to 0.92
Implementation Method 2
a degree of graphitization Gr of the carbon material that is measured in an X-ray diffraction analysis method
Data Source
AI summary
A negative electrode active material includes a carbon material, where the carbon material has a specific degree of graphitization and aspect ratio distribution. A degree of graphitization Gr of the carbon material measured by an X-ray diffraction analysis method is 0.82 to 0.92, and based on a total quantity of particles of the carbon material, a proportion of particles with an aspect ratio greater than 3.3 in the carbon material is less than 10%. The negative electrode active material helps to improve cycle performance of the electrochemical apparatus. FIG. 1.