Graphite As an Anode Material in Li-Ion Batteries
In our daily lives, lithium-ion batteries are what supply us with energy – whether in electric cars or laptops. They consist of an anode on one side and a cathode on the other. Lithium ions flow from the cathode to the anode when charging and discharge happens. This requires special materials that ensure the battery’s cycle life – and graphite is a perfect fit for this application.
Graphite is available either in natural flake or synthetic form. Both types are used for the anode material in lithium-ion batteries. However, manufacturers tend to favor synthetic graphite due to its superior consistency. Graphite purity is essential as it determines the battery’s performance. Its crystalline structure forces the lithium ions to bind to it in an adsorption process, resulting in a high energy density and stable cycling durability.
Achieving high purity graphite is difficult. It is often processed through acid/caustic leaching or thermal purification using power generated by coal/lignite-fired plants. In addition, the process is very energy intensive and off gas scrubbing is almost non-existent.
Graphite surface damage from the SEI layer deteriorates its performance in Li-ion batteries and needs to be eliminated. This is why effective surface treatments are necessary. They help to modify the surface structure, reduce irreversible capacity loss and improve capacities in batteries. It is also important to take a holistic approach that takes into account various failure mechanisms that interact with each other and aggravate SEI layer damage in batteries.
