One-dimensional Te nanostructures as fast anode materials of potassium ion batteries

Potassium-ion batteries (PIBs) exhibit a comparable performance to the commercial lithium-ion batteries. The development of the suitable anode materials for PIBs is long-requested to improve the performance of batteries. In our work, the controlled fabrication of different one-dimensional (1D) Te nanostructures including nanotubes and nanorods is realized by tuning the pH of maternal synthetic solutions. Such a 1D preferential growth nature favors the fast electronic transportation along the longitudinal direction compared with other planar or spherical nanostructures. Moreover, in contrast to nanorods, the Te nanotubes are characterized with hollow channels and thus can release the stress generated during the discharging, retaining the integrity of electrodes. When working as the anode materials for PIBs, the Te nanotube electrode is superior to the nanorod counterpart. Specifically, it offers the cycling performance with about 218.7 mAh g⁻¹ after 500 cycles at 0.1 A g⁻¹ and excellent rate capability (113.2 mAh g⁻¹ at 2.5 A g⁻¹). Even cycling for 1000 cycles at 1 A g⁻¹, the Te nanotube electrode still delivers a notable capacity retention rate of 99.9% with the final discharge capacity stable at 112 mAh g⁻¹.