To meet the demands of next-generation high-performance lithium-ion batteries, graphitized petroleum coke requires improvements in rate performance, cycle stability, low-temperature performance, structural strength, initial efficiency, and cost-effectiveness in terms of production processes. The specific analysis is as follows:
I. Enhancing Rate Performance and Cycle Stability
Problem: During the charging and discharging processes, the insertion and extraction of lithium ions in graphitized petroleum coke can cause expansion and contraction of the graphite layers. Over long-term cycling, this may lead to structural damage, affecting cycle stability. Improvement Directions:
- Particle Structure Reorganization: Select appropriate needle coke precursors and use easily graphitizable materials such as pitch as carbon sources for binders. By treating these materials in a rotary furnace, several needle coke particles can be bonded together to form secondary particles with appropriate particle sizes, followed by graphitization. This approach effectively reduces the material’s crystallite orientation index (OI value) and enhances the diffusion path for lithium ions, thereby improving rate performance.
- Surface Coating Modification: Coat graphitized petroleum coke with materials such as amorphous carbon, metal oxides, or polymers to construct “core-shell” structured particles. The coating layer can isolate direct contact with the electrolyte, reduce surface active sites, lower specific surface area, and simultaneously enhance the insertion and diffusion capabilities of lithium ions, thereby improving cycle stability.
II. Enhancing Low-Temperature Performance
Problem: In low-temperature environments, the diffusion rate of lithium ions in graphitized petroleum coke decreases, leading to a decline in battery performance. Improvement Directions:
- Doping with Soft Carbon: Incorporating a certain proportion of soft carbon into the graphite anode can improve the battery’s low-temperature charging performance. Soft carbon possesses an amorphous structure with large interlayer spacing and good compatibility with the electrolyte, resulting in excellent low-temperature performance. However, the doping ratio should be carefully controlled to balance low-temperature performance and cycle life.
- Optimizing Electrolyte Formulation: Optimize the electrolyte formulation by adding novel additives or altering the solvent composition to reduce the electrolyte’s viscosity at low temperatures and enhance the diffusion rate of lithium ions.
III. Improving Structural Strength and Stability
Problem: Highly graphitized carbon materials, although possessing high capacity and stable charge-discharge platforms, may exhibit poor cycle performance and low-temperature performance. Improvement Directions:
- Controlling Graphitization Degree: During the graphitization process, the degree of graphitization should be controlled to retain some amorphous structures between microcrystals, thereby maintaining a certain level of structural strength.
- Introducing Nanostructures: By constructing nanostructures or porous structures, the number of insertion and extraction channels for lithium ions can be increased, enhancing the material’s structural stability.
IV. Improving Initial Efficiency and Reducing Costs
Problem: As an anode material, graphitized petroleum coke may exhibit low initial efficiency and high production costs. Improvement Directions:
- Surface Oxidation Treatment: Treat graphitized petroleum coke with a strong oxidizing agent solution to oxidize and passivate surface active potentials and reducing functional groups, thereby improving initial efficiency.
- Optimizing Production Processes: Improve production processes such as calcination and graphitization to reduce production costs and enhance production efficiency.
Post time: Oct-16-2025