Graphite As an Anode or Cathode for Li-Ion Batteries
The fundamental function of graphite within an electrochemical battery is the reversible intercalation of lithium ions into vacant sites in its crystal lattice. Without this property, lithium ion batteries would not be viable as they are today.
Graphite is an inert carbon material which is not reactive to most chemicals in the electrolytes used in the cell. This means that it will not form chemical compounds which could affect battery performance or even cause a fire in the event of an internal short circuit. It also satisfies the conduction requirement primarily required by an anode material for lithium ion batteries.
With a wide variety of industrial and consumer applications, graphite is the most commonly used anode material in Li-ion batteries, with approximately 55 percent of the market attributed to natural and 50 percent to synthetic graphite. The vast majority of the graphite produced is mined in China and sold to manufacturers worldwide.
A mixed slurry of LMO@Gn, carbon black (Timcal Super P) and polyvinylidene fluoride (PVDF; Solef 5130) in N-methyl-2-pyrrolidone was ball milled to a stoichiometric ratio in a stainless vial to yield a partially lithiated LMO@Gn/carbon black/PVDF anode. The lithiation extent was measured as 0.2Q at the lowest potential region during pre-charging and 1.0Q during discharging (Supplementary Fig. 1).
This resulted in higher rate capability and energy density, lower first cycle irreversible capacity loss and longer cycle life. Graphite particle morphology was optimized to increase packing efficiency and conductivity. The morphology was also studied using scanning electron microscopy to visualize the distribution of the particles and determine their surface structure, which in turn was used to quantify Mn deposits.
