Lawrence Berkeley National Laboratory

Lithium-ion and sodium-ion batteries (LIBs and SIBs) are crucial in our shift toward sustainable technologies. In this work, the potential of layered boride materials (MoAlB and Mo₂ AlB₂ ) as novel, high-performance electrode materials for LIBs and SIBs, is explored. It is discovered that Mo₂ AlB₂ shows a higher specific capacity than MoAlB when used as an electrode material for LIBs, with a specific capacity of 593 mAh g^-1 achieved after 500 cycles at 200 mA g^-1 . It is also found that surface redox reactions are responsible for Li storage in Mo₂ AlB₂ , instead of intercalation or conversion. Moreover, the sodium hydroxide treatment of MoAlB leads to a porous morphology and higher specific capacities exceeding that of pristine MoAlB. When tested in SIBs, Mo₂ AlB₂ exhibits a specific capacity of 150 mAh g^-1 at 20 mA g^-1 . These findings suggest that layered borides have potential as electrode materials for both LIBs and SIBs, and highlight the importance of surface redox reactions in Li storage mechanisms.