Two-dimensional penta-siligraphene with high performance for non‑lithium metal ions batteries anode materials

Abstract

Non‑lithium metal ion batteries (NLMIBs) will play an important part in sustainable energy and grid storage. Searching for high-performance electrode materials are critical to the development of NLMIBs. From first-principles calculations, we predict that penta-siligraphene (P-Si2C4), a new two-dimensional (2D) layered material obtained by replacing the sp3 C atoms in penta-graphene with Si atoms, can be used as a promising anode material for NLMIBs including Na-, K-, Rb-, Ca-, Sr- and Ba-ion. The theoretical specific capacities for Na, Sr, Ba, Rb, K and Ca ions are 514.3, 1028.7, 1028.7, 578.6, 1028.7 and 2057.3 mA h g−1, respectively. The metal-ion intercalation potentials (0.1–1.0 V) are suitable for battery application. After metal-ions adsorbed, the electronic structures of P-Si2C4 become metallic indicating of good electronic conductivity of the anode. The metal-ion/vacancy diffusion energy barriers on the surface of P-Si2C4 are relatively small and ensure good rate performance. Our research offers a promising high performance anode material for the application in NLMIBs.