Nature of bismuth and antimony based phosphate nanobundles/graphene for superior potassium ion batteries

A novel architecture with bismuth (Bi) and antimony (Sb) based phosphate nanobundles well dispersed on graphene nanosheet is devised as outstanding anode for potassium-ion batteries (PIBs). The Bi and Sb based (in a ratio of 47:53) phosphate nanobundles can deliver a favourable cycling performance for 400 cycles under 500 mA g(-1), obtaining a gravimetric capacity of 288 mAh g(-1) with a remarkable capacity maintenance of 99%, in addition to displaying promising voltage plateaus. Meanwhile, it shows a superior performance in the full battery test, reaching an admired capacity of 372 mAh g(-1) at 100 mA g(-1). Nature of Bi and Sb based phosphate nanobundles during battery operation, including the lattice evolution, chemical bond cleavage, and phase transformation, is revealed. This study is notable for providing a promising anode for PIBs, and unveiling the nature of potassium storage mechanism of bismuth and antimony based phosphate, which is significant for the electrode development in PIBs.

Automated summary

A novel architecture with well dispersed bismuth and antimony based phosphate nanobundles on graphene nanosheet is designed as an outstanding anode for potassium-ion batteries. The nanobundles exhibit favorable cycling performance, remarkable capacity maintenance, promising voltage plateaus, and superior overall battery performance. The study also reveals the nature of the potassium storage mechanism of bismuth and antimony based phosphate nanobundles, providing important insights for electrode development in potassium-ion batteries.