Effects of lithium on the electronic properties of porous Ge as anode material for batteries

Recently, the need of improvement of energy storage has led to the development of Lithium batteries with porous materials as electrodes. Porous Germanium (pGe) has shown promise for the development of new generation Li-ion batteries due to its excellent electronic, and chemical properties, however, the effect of lithium in its properties has not been studied extensively. In this contribution, the effect of surface and interstitial Li on the electronic properties of pGe was studied using a first-principles density functional theory scheme. The porous structures were modeled by removing columns of atoms in the [001] direction and the surface dangling bonds were passivated with H atoms, and then replaced with Li atoms. Also, the effect of a single interstitial Li in the Ge was analyzed. The transition state and the diffusion barrier of the Li in the Ge structure were studied using a quadratic synchronous transit scheme.