Lithium & The Future, page-73

Lithium-ion batteries

1. The LIBs on the market today primarily use graphite or silicon anodes and a liquid electrolyte. A lithium anode has been the holy grail for a long time because it can store a lot of energy in a small space (i.e. it has a high energy density) and is very lightweight. Unfortunately, lithium heats up and expands during charging, causing leaked lithium ions to build up on a battery’s surface. These growths short-circuit the battery and decrease its overall life. Researchers at Stanford recently made headway on these problems by forming a protective nanosphere layer on the lithium anode that moves with the lithium as it expands and contracts.

Movement of lithium ions and electrons in a lithium-ion battery during charging and use.
Source: Argonne National Laboratory. Used under Creative Commons license.