Flexible Mn0.5Ti2(PO4)3/C Nanofibers Film with Superior Cycle Stability for Potassium-ion Batteries

The first-principles calculations indicate that Mn0.5Ti2(PO4)3 is more suited to potassium-ion storage because of its lower energy gap than KTi2(PO4)3. Flexible Mn0.5Ti2(PO4)3/C nanofibers film (F-MTP/C NFF) has been firstly synthesized via electrospinning and applied to potassium-ion batteries as self-standing anode. Integral carbon conductive network, unique one-dimensional nanostructure, and exceptional mechanical flexibility give F-MTP/C NFF outstanding potassium-ion storage performance. Impressively, the self-standing F-MTP/C NFF electrode delivers a high specific capacity of 218 mAh g-1 at 0.02 A g-1 and shows ultra-long cycle stability of 2000 cycles at 1 A g-1. This work may give a new sight into developing NASICON-type Ti-based materials as flexible electrode for potassium-ion batteries.