Surface Redox-Active Organosulfur-Tethered Carbon Nanotubes for High Power and Long Cyclability of Na–Organosulfur Hybrid Energy Storage
Milan Jana, Jae Min Park, Manikantan Kota, Kang Ho Shin, Harpalsinh H. Rana, Puritut Nakhanivej, Jia‐Qi Huang, Ho Seok Park
Abstract
Despite the clear benefits of Na and S active materials, Na–S hybrid energy storage devices have yet to be exploited, and existing Na–S batteries cannot provide fast kinetics and long-term stability. Herein, we describe chemical and electronic coupling of the redox-active organosulfur moiety (−S–S–S−) with carbon nanotube (CNT) networks for high power and long cyclability of Na–organosulfur hybrid energy storage devices. The facile and reversible surface redox kinetics of organosulfur-tethered CNT is associated with a two-electron transfer toward the formation of low-order polysulfide, as confirmed by in situ and ex situ analyses. The specific capacitance of SOS-OCNT is 377 F g–1 (94% of theoretical capacitance) and 61.3% of capacitance is retained at 10 A g–1. The Na–organosulfur hybrid full cells deliver an ultrahigh power density of 13.4 kW kg–1 and high energy density of 27 Wh kg–1 over 50000 cycles.