Graphene-like silicon carbide layer for potential safe anode lithium ion battery: A first principle study

The persistent safety challenge accompanying the use of carbon as anode material for lithium-ion batteries is a major setback in its use for energy storage applications unless a suitable replacement is found. Here we investigate the structural, electronic and electrochemical properties of graphene-like Silicon Carbide (SiC) using density functional theory (DFT). The result shows that SiC is an indirect band gap semiconductor with a band gap energy of 2.35 eV. Strong adsorption of Li on SiC is also observed with a transition from semiconducting to metallic phase upon full lithiation. The SiC also retains its structure after adatom adsorption indicating good cycling stability. The calculated value of 1.5 eV for the open circuit voltage is comparable with those of TiO2. At this value, the metal lithium deposition, dendrite formation and formation of solid electrolyte interface leading to battery short circuits and other battery problems should be avoided. The theoretical capacity at the maximum concentration is 122mAhg−1, comparable to other two-dimensional (2D) materials. These findings suggest graphene-like SiC layer as a potential safe anode material for Li-ion batteries.