Other anode materials

We are now going to look at some other potential anode materials.

Lithium titanate (LTO)

A lithium-titanate (LTO, (Li_{4}Ti_{5}O_{12})) batteries are rechargeable batteries that are much faster to charge than other LIBs. They differ from other LIBs because they use LTO on the anode rather than carbon. This is advantageous because LTO does not create a solid electrolyte interface layer, which acts as a barrier for Li ions when moving to and from the anode. This allows LTO batteries to be recharged more quickly and to provide higher currents when needed. A disadvantage of LTO batteries is their much lower capacity ((60–110 hspace{0.1 cm} Wh hspace{0.1 cm} kg^{-1})) and voltage (2.3 V) than those used in conventional LIBs. LTO batteries are being used in EVs and other applications.

Silicon

Silicon anodes are widely studied because of their high abundance and the fact that silicon is inexpensive. Further, when alloyed with lithium it exhibits a theoretical capacity of (sim 3600 hspace{0.1 cm} mAh hspace{0.1 cm} g^{-1}), nearly 10 times the energy density of graphite electrodes, which exhibits a maximum capacity of (372 hspace{0.1 cm} mAh hspace{0.1 cm} g^{-1}) in the fully lithiated state of (LiC_6). The major obstacle in the commercialization of silicon as anode material for LIBs is the high volumetric changes and the formation of a solid electrolyte interface (SEI).

Other carbon materials

As mentioned, graphite is the most commonly used negative electrode material in commercial LIBs. Other potential carbon materials that can be used in batteries are graphene and carbon nanotubes. Recently, hard carbon has been reported as a potential new anode material for next-generation batteries.

LIBs typically consist of natural and synthetic graphite as anode materials. Graphite exhibits a theoretical energy density of (372 hspace{0.1 cm} mAh hspace{0.1 cm} g^{-1}). So far, graphite is the most commonly used anode material in LIBs, but an alternative is needed due to the high carbon footprint of natural graphite. For instance, challenges related to the purification of graphite, such as the need for HF, have been widely recognized. Several potential alternative approaches for the use of graphite include the use of biomass-based materials for hard carbons, biomass graphitization, and/or the use of metallic Li anode instead of graphite anode.