NiS2/FeS Holey Film as Freestanding Electrode for High-Performance Lithium Battery

5 years ago

NiS2/FeS Holey Film as Freestanding Electrode for High-Performance Lithium Battery

Kun Liang, Samuel T. De Oliveira, Yilun Li, Le Zhou, Yang Yang, Yong-Ho Sohn, Shoufeng Zhang, Nina Orlovskaya, Kyle Marcus

In this work, a freestanding NiS2/FeS holey film (HF) is prepared after electrochemical anodic and chemical vapor deposition treatments. With the combination of good electrical conductivity and holey structure, the NiS2/FeS HF presents superior electrochemical performance, due to the following reasons: (i) Porous structure of HF provides a large surface area and more active sites/channels/pathways to enhance the ion/mass diffusion. Moreover, the porous structure can reduce the damage from the volumetric expansion. (ii) The as-prepared electrode combines the current collector (residual NiFe alloy) and active materials (sulfides) together, thus reducing the resistance of the electrode. Additionally, the good conductivity of HF can improve electron transport. (iii) Sulfides are more stable as active materials than sulfur, showing only a small capacity decay while retaining high cyclability performance. This work provides a promising way to develop high energy and stable electrode for Li-S battery. A freestanding and binder-free NiS2/FeS highly porous thin film is developed as a cathode in a Li-S battery. A high volumetric capacity of 580 mA h cm−3 and a long-term stability over 5000 discharge–charge cycles are achieved due to enhanced ion/mass diffusion and reduced volume expansion inside porous metal sulfide materials.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/aenm.201701309