Emerging as a new family of two-dimensional materials, transition-metal borides, namely MBenes, are expected to possess outstanding physical and chemical properties owing to their layered structures analogous to MXenes. Here, we explore the electrochemical properties of ScB and TiB monolayers as anode materials for lithium- and sodium-ion batteries by density-functional theory calculations. Our results reveal that Li/Na ions can be stably adsorbed on surfaces of both monolayers with moderate adsorption energy, rapid charge/discharge rate, higher storage capacity, and much lower diffusion energy barrier (0.108 eV for Li ion on ScB, 0.105 eV for Li ion on TiB, 0.072 eV for Na ion on ScB, and 0.063 eV for Na ion on TiB) as compared with other MBene monolayers currently reported. Meanwhile, the open-circuit voltages all fall in the range of 0–1 V for Li/Na ion on the monolayers, which may effectively suppress the formation of Li/Na dendrite on anodes during the charge/discharge process. Besides, at room temperature, Li adatoms could be adsorbed on the monolayers more stably than Na adatoms. Our work demonstrates that ScB and TiB monolayers should be promising two-dimensional anode materials for lithium-ion batteries and are less suitable for sodium-ion batteries. These results advance our understanding on the electrochemical performances of MBenes and provide important insights into the design and development of high-performance electrode materials for metal-ion batteries.

中文翻译：

---

ScB 和 TiB MBenes 作为高性能金属离子电池负极材料的计算评估

作为一个新的二维材料家族，过渡金属硼化物，即MBenes，由于其类似于MXenes的层状结构，有望具有出色的物理和化学性能。在这里，我们通过密度泛函理论计算探索 ScB 和 TiB 单层作为锂离子和钠离子电池负极材料的电化学性能。我们的结果表明，Li/Na 离子可以稳定地吸附在两个单层膜的表面上，具有中等吸附能、快速充电/放电速率、更高的存储容量和更低的扩散能垒（Li 离子在 ScB 上为 0.108 eV，在 ScB 上为 0.105 eV与目前报道的其他 MBene 单层相比，TiB 上的锂离子，ScB 上的 Na 离子为 0.072 eV，TiB 上的 Na 离子为 0.063 eV。同时，单层锂/钠离子的开路电压均在0-1 V范围内，这可以有效抑制充电/放电过程中负极上锂/钠枝晶的形成。此外，在室温下，锂吸附原子比钠吸附原子更稳定地吸附在单分子层上。我们的工作表明，ScB 和 TiB 单层应该是有前途的锂离子电池二维负极材料，不太适合钠离子电池。这些结果加深了我们对 MBenes 电化学性能的理解，并为金属离子电池高性能电极材料的设计和开发提供了重要的见解。在室温下，Li吸附原子比Na吸附原子更稳定地吸附在单分子层上。我们的工作表明，ScB 和 TiB 单层应该是有前途的锂离子电池二维负极材料，不太适合钠离子电池。这些结果加深了我们对 MBenes 电化学性能的理解，并为金属离子电池高性能电极材料的设计和开发提供了重要的见解。在室温下，Li吸附原子比Na吸附原子更稳定地吸附在单分子层上。我们的工作表明，ScB 和 TiB 单层应该是有前途的锂离子电池二维负极材料，不太适合钠离子电池。这些结果加深了我们对 MBenes 电化学性能的理解，并为金属离子电池高性能电极材料的设计和开发提供了重要的见解。