First Principles Study of Penta-siligraphene as High-Performance Anode Material for Li-Ion Batteries

Abstract

From first principles calculations, a novel pentagonal Si/C complexity is predicted to have potential applications as a promising anode material for Li-ion batteries. It is found that the structural and thermal stability of the penta-siligraphene (P-Si 2 C 4 ) is better than penta-graphene that is composed of C atoms only. Electronic band structure analysis shows that the empty C-2 p z state in the P-Si 2 C 4 provides space to accommodate and stabilize electrons from Li, which makes Li storage energetically favorable. As a result, four Li atoms can be stored by one formula unit of the P-Si 2 C 4 , corresponding to a theoretical gravimetric Li storage capacity of 1028.7 mAhg −1 . The metallic electronic structures of the Li-adsorbed P-Li x Si 2 C 4 as well as very small Li migration energy barriers are beneficial for fast charge/discharge performance of the battery. The mechanism on the Li adsorption interaction on the P-Si 2 C 4 is discussed. These results demonstrate a novel strategy to design two-dimensional Si/C complex anode materials for high-performance Li-ion batteries. Electronic supplementary material The online version of this article (10.1186/s11671-019-3097-5) contains supplementary material, which is available to authorized users.

Density Functional Theory Investigation of Mixed Transition Metals in Olivine and Tavorite Cathode Materials for Li-Ion Batteries

“…However, we may consider that the corresponding structures are dynamically stable based on energy-related calculations. Note that small imaginary frequencies appeared for some dynamically stable materials such as MoS 2 , germanene, arsenene, and ZrO 2 . − For comparison purpose, we also calculated phonon dispersion for LiMnPO 4 . It can be seen that to some extent, phonon dispersion of experimentally realizable and dynamically stable LiMnPO 4 also exhibited imaginary frequencies.…”

First-principles study of two-dimensional C-silicyne nanosheet as a promising anode material for rechargeable Li-ion batteries

“…36 Grimme's corrected form, DFT-D3 37 is implemented to consider the van der Waals interactions while performing adsorption studies. The average adsorption of Li (adatom) on the C-silicyne monolayer is calculated using the formula 38 :where E CS–Li represents the total energy of the Li loaded C-silicyne monolayer, E CS denotes the bare monolayer's energy, E Li is the energy of Li metal from its bulk phase, and n denotes the number of Li atoms loaded.…”

Strain- and electric field-enhanced optical properties of the penta-siligraphene monolayer

“…The structure was formed by substituting two sp 3 carbon atoms with Si atoms in the PG monolayer. 41 Fig. 1 illustrates the optimized structure of the PSG monolayer.…”

“…This structure has a tetragonal lattice with group space P% 42 1 m (number 113) with a unit cell consisting of six atoms (two Si and four C) with two different hybridizations, sp 2 (C) and sp 3 (Si). 7,41 The optimized lattice constants of the p-Si 2 C 4 monolayer are a = b = 4.40 Å, and the Si-C and C-C bond lengths are 1.90 Å and 1.36 Å, respectively. These results are in good agreement with previous theoretical results.…”

“…4) of p-Si 2 C 4 is 2.38/2.82 eV; the value of HSE06 is in good agreement with previously reported values. 8,41,50,51 From Fig. 3 and 4, the HSE06 and GW correct only the bandgap energy without any change in the dispersion around the band edges.…”