High Conductivity Spherical Graphite For Lithium Battery

Spherical Graphite Overview

The global demand for cost-effective energy storage solutions and home energy storage continues to drive the growth of the graphite flake market. Typically, flake graphite is shaped into a rounded, spherical shape by a mechanical attrition process. The rounded shape of SPG allows for more efficient packaging of particles in a LiB anode, which increases the energy and recharge capacity of the LiB. Spherical graphite is a crucial ingredient in the efficient operation of lithium-ion batteries. SPG is the key component of the anode of a LiB which without, the LiB would not function.

Historically SPG has been derived from synthetic graphite, a significantly more costly option when compared against natural flake graphite (NFG).

Purification and Coating

The spheroidical graphite is then purified to remove deleterious elements including SiO2, Iron, Sulfur, and other metal elements. Various purification techniques are used in this process. These include aggressive acid purification with hydrofluoric acid, as well as thermal purification using high-temperature furnaces. Both of these methods have their advantages and disadvantages.

Aggressive acid purification is a low cost, effective method of purification, but due to the nature of the acids used, including hydrofluoric acid, they present a toxic and dangerous working environment, as well as an environmental management challenge. Thermal purification is an electrical thermal process which is fairly expensive compared to acid purification, but is significantly safer and does not impact the environment.

After purification, Purified SPG is coated to assist with improving the surface and area of the particles. Many LiB manufacturers used their own proprietary technology for coating. The coated, purified SPG is then packed into the shape of the anode required for the LiB batteries.