Overview
This lecture covers the value chain, processing, and critical role of natural graphite in batteries, with a focus on its sourcing, processing steps, market trends, and future opportunities, particularly in Australia.
Battery Value Chain Overview
- CSIRO performs full battery value chain research, from mining to recycling in Australia.
- Key battery minerals: lithium, cobalt, nickel, manganese, vanadium.
- Battery components include cathode (e.g., NCA, NMC, LFP), anode (mainly graphite), electrolyte, and lithium metal for next-gen tech.
- Graphite is critical as the dominant anode material in lithium-ion batteries.
Graphite Properties and Importance
- Graphite is a layered form of carbon where lithium is stored between layers.
- Amorphous carbon is conductive but does not store energy.
- Synthetic graphite requires energy-intensive processing from petroleum sources.
- Natural graphite is primarily found in China, Russia, Africa, Scandinavia, and Australia.
Processing Natural Graphite for Batteries
- Mining and concentration involve crushing, flotation, and screening.
- Spheronization turns flakes into round particles, improving energy density and performance.
- Purification removes impurities to achieve >99.95% graphite.
- Carbon coating further optimizes surface properties and battery life.
- Final step is forming an anode by mixing graphite with binders and coating onto copper foil.
Market Trends and Sustainability
- China currently dominates graphite processing and purification.
- Demand for graphite is rising due to increased battery production for energy storage and EVs.
- Recycled graphite is gaining interest but is limited by available volume.
- There is a trend toward blending natural and synthetic graphites.
- New purification methods, such as caustic processing, are in development for sustainability.
Challenges and Opportunities
- Artificial graphite is more stable but energy-intensive and polluting.
- Natural graphite faces issues like swelling and SEI degradation but is improving via processing.
- The graphite market is pressured by price and supply chain constraints.
- Diversification of supply chains is driving investment outside China.
- Australia is well-positioned to enter the battery graphite supply chain.
Key Terms & Definitions
- Graphite — A crystalline form of carbon used as the anode in lithium-ion batteries.
- Spheronization — The process of shaping graphite flakes into round particles for improved battery packing.
- SEI (Solid Electrolyte Interface) — Layer formed on anode surface impacting battery efficiency and life.
- Purification — Processes to remove impurities from graphite to battery-grade.
- Carbon Coating — Thin layer added to graphite particles to reduce unwanted reactions and improve performance.
- Artificial (Synthetic) Graphite — Graphite produced from petroleum coke at high temperatures.
- Natural Graphite — Graphite mined from natural ore bodies.
Action Items / Next Steps
- Review purification techniques for sustainability (e.g., caustic processing).
- Investigate current graphite projects and market diversification trends.
- Explore impacts of supply chain policy changes on battery material sourcing.