Uniform Bi-Sb Alloy Nanoparticles Synthesized from MOFs by Laser Metallurgy for Sodium-Ion Batteries

We report the design and synthesis of a bismuth metal organic framework (MOF), MOF-836. This MOF is loaded with Sb salts in its pores and is used as the precursor for the production of Bi-Sb alloy nanoparticles by the nanoscale laser metallurgy method in the air. The resulting Bi-Sb alloy nanoparticles, Bi1-xSbx(from MOF-836), exhibit uniform particle sizes of 30 +/- 10 nm, and their compositions are precisely controlled by tuning the content of Sb in MOF-836. These Bi-Sb alloys, along with the ones prepared from another Bi-MOF, CAU-7, were employed as anodes for sodium-ion batteries (SIBs). The nanosized Bi0.70Sb0.30(from MOF-836) alloys showed a specific capacity of 259.8 mAh g(-1) at 200 mA g(-1) after 500 cycles, and excellent cycling performance, capacity retention of 180.9 mAh g(-1) at 1 A g(-1) over 1000 cycles with a capacity loss of only 0.055% per cycle. This nanoscale laser metallurgy method using MOFs as precursors represents a new way to prepare alloy nanoparticles.