In Situ Formation of Co9S8 Nanoclusters in Sulfur-Doped Carbon Foam as a Sustainable and High-Rate Sodium-Ion Anode

• Published in: ACS applied materials & interfaces Vol. 11; no. 21; pp. 19218 - 19226
• Main Authors: Wang, Yunxiao, Wang, Yanxia, Wang, Yun-xia, Feng, Xiangming, Chen, Weihua, Qian, Jiangfeng, Ai, Xinping, Yang, Hanxi, Cao, Yuliang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 29.05.2019
• Subjects: anodes; batteries; carbon; carbonization; cobalt sulfide; foams; nanoparticles; sulfur; cobalt sulfides nanoclusters; ultrahigh rate capability; carbon foam; Co9S8 anodes; sodium ion batteries
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.9b05134

Transition-metal sulfides hold great promise as anode materials for sodium-ion batteries due to the high theoretical capacity and excellent redox reversibility based on multielectron conversion reactions. In this work, an elaborate composite, cobalt sulfide nanoclusters embedded in honeycomb-like sulfur-doped carbon foam (Co9S8@S-CF), is prepared via a facile sulfur-assisting calcination strategy, which tactfully induces the co-occurrence of in situ pore-forming, sulfidation, sulfur doping, and carbonization. Notably, sulfur-doped carbon foam (S-CF) possesses abundant voids, which are subject to construction of three-dimensional ionic/electronic pathways, leading to high sodium-ion accessibility and ultrafast sodium-ion/electron transportation toward Co9S8 nanoclusters. When worked as an anode in sodium-ion batteries, it delivers a remarkable capacity of 373 mA h g–1 over 1000 cycles at 0.25 C, achieving superior capacity retention of 80%. Furthermore, this anode could achieve unprecedented rate capability with a reversible capacity of 180 mA h g–1 at 50 C (20 A g–1), which significantly precedes those reported previously.