By Kevin Clemens – Presently, commercial lithium ion batteries use a carbon graphite anode electrode and a metal oxide cathode electrode. They are separated by a liquid organic solvent that can pass lithium ions between the electrodes while preventing electrons from making the journey. The organic solvent of the electrolyte is flammable—resulting in a potential for a fire in the event that a lithium ion battery is punctured.
The anode side of a lithium ion battery is made from layers of graphite. Lithium ions are inserted between the material’s layers during charging and are released during discharge. Battery researchers realize that replacing the graphite anode with metallic lithium would allow many more lithium ions to flow during discharge, producing a battery with at least twice the capacity. But during the charging stage of a lithium metal battery, spiky crystalline structures, called dendrites, form on the metal surface. These dendrites can grow through the liquid electrolyte, reaching the cathode and shorting out the battery.
A worldwide search is on for a solid or semi-solid electrolyte that can prevent dendrite growth while allowing the easy passage of lithium ions without conducting electrons. more>