Graphite GDIB Anode and Cathode Materials for Lithium-Ion Batteries
In lithium-ion batteries (LIBs), graphite is the anode material of choice. It is made from carbonaceous fillers bonded with carbon-yielding binders, extruded into rods, and baked to a high temperature in order to graphitize it. This process provides an amorphous structure with superior electrical and thermal properties.
Graphite offers a wide operating voltage window, good rate capability, and a relatively low self-discharge. Graphite anodes can also tolerate significant amounts of current. However, a major limitation of the current generation of graphite-based LIBs is the limited gravimetric and volumetric capacity relative to lithium metal. This can be partially remedied by modifying the surface of the graphite particles. This can be achieved through chemical treatments, ceramic materials, or gases followed by a heat treatment.
The working principle of GDIBs involves the reversible intercalation of lithium ions into open sites in the graphite cathode during charging. The lithium ions are transported from the anode to the cathode through a liquid electrolyte comprising lithium salts dissolved in polar organic solvents such as alkyl carbonates.
Currently, China dominates the world graphite market, producing more than 6.5 times more natural and synthetic graphite than its nearest competitor. The country is well positioned to benefit from the increasing demand for portable electronic devices and longer-range electric vehicles worldwide. However, the limited intrinsic specific capacity and safety issues associated with current commercial graphite anodes limit their application. As a result, silicon has been extensively researched as an alternative to graphite for battery applications.
