Cell Design and Materials: Li-Ion

Graphite Basic Technology and Information - Industry-standard Anode Material for Lithium Ion Batteries Graphite is the dominant active anode material due to its layered structure enabling reversible lithium intercalation. Both natural and synthetic graphite are employed industrially as anode, with properties tailored through processing and surface modification to meet specific cell performance requirements. Fully lithiated graphite LiC6 offers a theoretical maximum capacity of 372 mAh/g. Surface engineering (e.g., carbon coating) is widely used to improve conductivity, suppress parasitic reactions, and enhance cycling stability, particularly under fast-charging conditions.

NATURAL GRAPHITE

Production process: Natural flake graphite is mined, beneficiated via flotation, purified to battery-grade specifications, and spheroidized to form spherical purified graphite.

higher practical capacity and competitive rate performance can be achieved due to favorable particle morphology and + Slightly increased edge-plane exposure at the particle surface. defect density, impurity sensitivity, and broader material source variability can increase surface reactivity and challenge – Higher long-term stability and sustainability.

SYNTHETIC GRAPHITE

Production process: Carbonaceous precursors (petroleum and needle coke) are carbonized and graphitized at high temperatures followed by refinement, yielding tailored microstructure.

+ Higher purity, lower thermal expansion, and better thermal stability lead to higher cycle life. – High production energy demand and petrochemical feedstock dependence increase cost and environmental footprint. CARBON COATING

Production process: Liquid- or gas-phase carbon precursors are pyrolyzed at 8001100 °C under inert conditions to create a thin, conformal conductive coating on graphite particles.

optimized thin carbon coating improves electronic percolation and moderates surface reactivity, enabling more stable SEI + An formation, enhanced rate performance, and improved cycle life. processing steps and excessive coating thickness can increase cost and reduce volumetric energy density if not – Additional carefully controlled. Source: Jakob Asenhaeur et al 2020, The success story of graphite as a lithium-ion anode material... Sustainable Energy & Fuels, 411, 53875416. K Zaghib et al 2003 Purification process of natural graphite... Journal of Power Sources, 119121, 815. Seong Jin An et al 2016 The state of understanding of the lithium-ion-battery graphite solid electrolyte interphase... Carbon, 105, 5276. Battery Report 2023, Battery Report 2024

PROPERTIES PERFORMANCE LINKAGE Key graphite attributes - including particle size distribution, tap density, surface area, and metallic/ magnetic impurity levels - govern electrode packing density, SEI stability, lithium-ion transport, and safety, thereby defining critical trade-offs among gravimetric energy density, volumetric energy density, power capability, and fast-charging performance.

APPLICATIONDRIVEN GRAPHITE SELECTION

High energy density EV High tap density graphite with controlled surface area.

Fast charging: Optimized PSD, edge-plane exposure, and carbon coating.

Long cycle life / ESS High-purity, structurally uniform graphite with stable SEI.

Cost-sensitive systems: Blended natural-synthetic graphite solutions.

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