Bare W-based MXenes (WCrC and MoWC) anode with high specific capacity for Li and Mg-ion batteries

Abstract

The emergence of double transition metal MXenes (DTMs) has addressed the challenges associated with the high molar weight and non-metallic characteristics of early transition metal MXenes. In this study, we investigate the performance of WCrC and MoWC, DTMs, as anodes in Li/Mg-ion batteries (LIBs/MIBs) using first-principles calculations. The synergistic effect between the dual metal terminals is analyzed. Our findings reveal that the W terminal provides good electronic conductivity, while the Mo/Cr terminal reduces the molar mass, leading to enhanced energy density. The theoretical capacitance values are 648.81 mAh g−1 (WCrC anode) and 551.82 mAh g−1 (MoWC anode) in LIB, and 432.54 mAh g−1 (WCrC anode) and 367.88 mAh g−1 (MoWC anode) in MIBs. Both anodes exhibit low diffusion barriers with 0.045 eV for Li and 0.079 eV for Mg. They also maintain structural rigidity throughout the battery cycle. This study highlights the crucial role of the dual metal transition terminal synergistic effect in MXenes, influencing adatom adsorption behavior, reducing molar mass, and lowering diffusion barriers. These results contribute to the advancement of MXene surface engineering and offer valuable insights for battery research.

Theoretical prediction of two-dimensional CrSi2N4 as a potential anode material for Na-ion batteries

“…In recent years, two-dimensional (2D) metal compounds with enhanced ion transport and high electronic conductivity, stood out as promising anode candidates for metalion batteries [10][11][12][13][14]. 2D transition metal dichalcogenides (TMDs), such as MoS 2 [12], V 2 C [15], Mo 2 C [16], show excellent Li/Na storage properties.…”

Creation of a boron carbide-based Ti3AlBC (312) MAX phase: a route to novel MXenes for energy storage

“…The crystal structure of the identified MAB phases motivated the synthesis of boron-based MAX phases on the basis of the theory that ‘increasing boron concentration can introduce boron-to-boron bonding and therefore increase thermodynamic stability.’ It was reported that the high lattice matching induced large Li and Na storage and the W-based MXene anode provided high specific capacity for Li and Mg-ion batteries. 15,16 In many situations, the boron nitride (BN) based MXenes show better characteristics than the carbides for K, Ca, and Mg ion storage, indicating their possible usage in non-Li battery applications. Furthermore, traditional MAX phases have thus far been limited to carbides and/or nitrides.…”