This nearly doubles the battery’s energy density. One option being researched is coating the silicon with graphene (single-atom-thick sheets of carbon), as the graphene sheets can ‘slide’ against each other, and compensate for the expansion and contraction of the silicon. Solving this major problem promises to produce a battery with a significantly better energy density than a standard lithium-ion battery with a graphite anode. Over time, this repeated expansion and shrinking fractures and cracks the silicon anode and the battery has a very short lifespan. When the battery discharges, and the lithium ions are released from the silicon anode, the silicon shrinks. However, while its lattice structure can incorporate the lithium ions needed to drive a lithium-ion battery, the inclusion of lithium ions causes a significant increase in volume-more than 300 per cent. When compared to the traditional graphite electrode, silicon offers a theoretical tenfold increase in capacity.
Silicon (Si) offers a huge increase in energy storage capability when used as an anode material.
Variations upon a theme: new lithium-ion technologies Silicon anode
