Affiliation:
1. Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials School of Material Science and Engineering Shaanxi University of Science and Technology Xi'an Shaanxi 710021 China
2. Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers and School of Chemistry and Materials Fudan University Shanghai 200433 China
3. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
Abstract
AbstractCarbon materials, owing to their low cost, high conductivity, and good thermal and chemical stability, have been deemed as a promising anode candidate for potassium‐ion batteries. However, anomalous low‐voltage discharge situations in crystalline carbon materials imply uncertainty in the potassium storage mechanism. Herein, an overlooked scenario, i.e., potassium metal underpotential deposition (PMUPD), is disclosed in crystalline carbon materials for the first time. The study unveils the induction of interlayer pores on desolvation and PMUPD by insights from thermodynamics, kinetics, and experimental analyses. By manipulating the cutoff voltage to utilize partial PMUPD, a novel synergistic mechanism of co‐intercalation and PMUPD is revealed. A remarkable initial coulombic efficiency of 92% and a 65% capacity retention at 30C (80 mAh g−1) are realized in crystalline carbon anode. This work provides a new insight into the potassium storage mechanism of carbon anode and contributes to further research and application of the UPD behavior in other alkaline metal ion batteries.
Funder
National Natural Science Foundation of China