FeP Coated in Nitrogen/Phosphorus Co-doped Carbon Shell Nanorods Arrays as High-Rate Capable Flexible Anode for K-ion Half/Full Batteries

Building a proper flexible electrode with high cycling stability, rate capacity and initial coulombic efficiency (ICE) for flexible potassium-ion batteries (PIBs) remains a challenge. Herein, nitrogen/phosphorus co-doped carbon coated FeP nanorods arrays on carbon cloth (FeP@N, P-C NRs/CC) as high-rate capable flexible self-supporting anode was successfully fabricated. The composite electrode combines the advantages of FeP nanorods arrays (FeP NRs), carbon cloth (CC) and N, P co-doped carbon shell (N, P-C), which comprehensively improves the electrochemical stability of the flexible electrode, while the open space between FeP nanorods can facilitate electrolyte impregnation and enhance K+ transfer, thus effectively elevating the corresponding rate capability. For the FeP@N, P-C NRs/CC electrode, it delivers a reversible capacity of 388.8 mA h g-1 at 0.5 A g-1 up to 400 cycles. Even at 1.5 A g-1, it can still achieve a remarkable rate capacity of 346.9 mA h g-1. Moreover, the assembled soft-packed cell can always light the LED lights when it is bent at different angles, which exhibits excellent mechanical flexibility. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

In this study, a flexible self-supporting anode for potassium-ion batteries with high rate capacity and cycling stability was successfully fabricated. The design and structure of the electrode allows for easy electrolyte impregnation, enhancing the rate capability of the battery. Furthermore, the battery maintains excellent performance even when bent at different angles.