Cubic\nCrystal-Structured SnTe for Superior Li- and\nNa-Ion Battery Anodes

Abstract

A cubic crystal-structured\nSn-based compound, SnTe, was easily\nsynthesized using a solid-state synthetic process to produce a better\nrechargeable battery, and its possible application as a Sn-based high-capacity\nanode material for Li-ion batteries (LIBs) and Na-ion batteries (NIBs)\nwas investigated. The electrochemically driven phase change mechanisms\nof the SnTe electrodes during Li and Na insertion/extraction were\nthoroughly examined utilizing various <i>ex situ</i> analytical\ntechniques. During Li insertion, SnTe was converted to Li_4.25Sn and Li₂Te; meanwhile, during Na insertion, SnTe experienced\na sequential topotactic transition to Na_<i>x</i>SnTe (<i>x</i> ≤ 1.5) and conversion to Na_3.75Sn and Na₂Te, which recombined into the original SnTe\nphase after full Li and Na extraction. The distinctive phase change\nmechanisms provided remarkable electrochemical Li- and Na-ion storage\nperformances, such as large reversible capacities with high Coulombic\nefficiencies and stable cyclabilities with fast C-rate characteristics,\nby preparing amorphous-C-decorated nanostructured SnTe-based composites.\nTherefore, SnTe, with its interesting phase change mechanisms, will\nbe a promising alternative for the oncoming generation of anode materials\nfor LIBs and NIBs.