Phase Engineering of Nickel Sulfides to Boost Sodium- and Potassium-Ion Storage Performance |
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Authors: | Jingxing Wu Sailin Liu Yaser Rehman Taizhong Huang Jiachang Zhao Qinfen Gu Jianfeng Mao Zaiping Guo |
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Affiliation: | 1. Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, School of Mechanical, Materials, Mechatronics and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales, 2522 Australia;2. Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong, 250022 China;3. College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620 P. R. China;4. Australian Synchrotron, ANSTO, 800 Blackburn Rd, Clayton, 3168 Australia;5. Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, School of Mechanical, Materials, Mechatronics and Biomedical Engineering, University of Wollongong, Wollongong, New South Wales, 2522 Australia School of Chemical Engineering & Advanced Materials, The University of Adelaide, Adelaide, South Australia, 5005 Australia |
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Abstract: | Sulfides are promising anode candidates because of their relatively large theoretical discharge/charge specific capacity and pretty small volume changes, but suffers from sluggish kinetics and structural instability upon cycling. Phase engineering can be designed to overcome the weakness of the electrochemical performance of sulfide anodes. By choosing nickel sulfides (α-NiS, β-NiS, and NiS2) supported by reduced graphene oxide (rGO) as model systems, it is demonstrated that the nickel sulfides with different crystal structures show different performances in both sodium-ion and potassium-ion batteries. In particular, the α-NiS/rGO display superior stable capacity (≈426 mAh g−1 for 500 cycles at 500 mA g−1) and exceptional rate capability (315 mAh g−1 at 2000 mA g−1). The combined density functional theory calculations and experimental studies reveal that the hexagonal structure is more conducive to ion absorption and conduction, a higher pseudocapacitive contribution, and higher mechanical ability to relieve the stress caused by the volume changes. Correspondingly, the phase engineered nickel sulfide coupled with the conducting rGO network synergistically boosts the electrochemical performance of batteries. This work sheds light on the use of phase engineering as an essential strategy for exploring materials with satisfactory electrochemical performance for sodium-ion and potassium-ion batteries. |
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Keywords: | NiS NiS2 phase engineering potassium-ion batteries sodium-ion batteries |
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