Ilmenite is a naturally-occurring titanium-iron oxide, steel-gray material, and a major source of titanium dioxide. This has applications in paints, printing inks, fabrics, plastics, paper, sunscreen, food, and cosmetics, according to Wikipedia. Researchers in Cairo found distinct advantages, when they trialed an ilmenite anode instead of graphite.
Cost of Mining Ilmenite for Lithium-Ion Anodes
Graphite is the norm for lithium-ion battery anodes. This material is relatively rare, and quite expensive to mine. The Cairo researchers chose to trial ilmenite instead. This is because it is readily available in ‘black sand’, in beach and dune deposits from the Nile river, along Egypt’s Mediterranean coastline.
Anything that reduces the cost of lithium-ion batteries is a potential money spinner, provided this does not diminish their performance. The researchers obtained a supply of black sand, and carefully hand-ground it before conducting a series of tests. This what they found:
- Their ilmenite sample exhibited a capacity of 355.5 mAhg, improved cycle stability, good rate capability, and high coulombic efficiency.
- This meant the mineral had good storage capacity, and could recharge a number of times before its significant power began to fade.
- In other words, the finely ground ilmenite sample was a promising alternative to conventional graphite anodes in lithium-ion batteries.
The Alternative Anode Mineral For Lithium-Ion?
Bioengineer picks up the thread at this point. It agrees we have an alternative ilmenite anode, instead of graphite in theory at least. And moreover mining the soft, sandy environment is less environmentally harsh, aligning with the goal of sustainable energy storage.
The ilmenite mineral also has a lattice-like, crystal molecular structure, enabling natural intercalation of charge-carrying ions. This means it is able to store energy between its layers, and release it to the cathode as the parent battery cycles. So yes, it seems we do have an alternative.
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