Research Article www.acsami.org
Potassium-Ion Oxygen Battery Based on a High Capacity Antimony Anode William D. McCulloch, Xiaodi Ren, Mingzhe Yu, Zhongjie Huang, and Yiying Wu* Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
Downloaded via OPEN UNIV OF HONG KONG on January 29, 2019 at 09:09:01 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
S Supporting Information *
ABSTRACT: Recent investigations into the application of potassium in the form of potassium−oxygen, potassium−sulfur, and potassium-ion batteries represent a new approach to moving beyond current lithium-ion technology. Herein, we report on a high capacity anode material for use in potassium−oxygen and potassium-ion batteries. An antimony-based electrode exhibits a reversible storage capacity of 650 mAh/g (98% of theoretical capacity, 660 mAh/g) corresponding to the formation of a cubic K3Sb alloy. The Sb electrode can cycle for over 50 cycles at a capacity of 250 mAh/g, which is one of the highest reported capacities for a potassium-ion anode material. X-ray diffraction and galvanostatic techniques were used to study the alloy structure and cycling performance, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy were used to provide insight into the thermodynamics and kinetics of the K− Sb alloying reaction. Finally, we explore the application of this anode material in the form of a K3Sb−O2 cell which displays relatively high operating voltages, low overpotentials, increased safety, and interfacial stability, effectively demonstrating its applicability to the field of metal oxygen batteries. KEYWORDS: potassium ion, anode, alloy, antimony, K−O2, oxygen cell
■
INTRODUCTION With the global energy demand expected to double by 2050, the development of an energy storage solution becomes vital.1 Metal−oxygen batteries in particular have attracted interest for applications in transportation and stationary energy storage, which is largely due to their high theoretical energy density.2−6 For example, the Li−O2 battery has a theoretical specific energy of 3505 Wh/kg.7 Unfortunately, this goal has yet to be realized due to numerous challenges such as electrolyte instability, poor cycling efficiency, and low rate capability.2,4,8 These problems stem from the Li2O2 peroxide discharge product, which is thought to have a low electronic conductivity.2,9 It is the decomposition of this peroxide that leads to a high polarization upon charging (typically ∼1.3 V). One solution is to use larger cations (e.g., Na+ and K+) to stabilize the superoxide discharge product.9 In 2013, we reported on the first K−O2 battery based on a KO2 discharge product and only a small polarization upon charging (
