Zhang, F, Xiong, P, Guo, X, Zhang, J, Yang, W, Wu, W, Liu, H & Wang, G 2019, 'A nitrogen, sulphur dual-doped hierarchical porous carbon with interconnected conductive polyaniline coating for high-performance sodium-selenium batteries', Energy Storage Materials, vol. 19, pp. 251-260.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier B.V. Sodium-selenium (Na-Se)battery has been emerging as a new rechargeable energy storage system with high capacity, low cost and high rate capability. However, the shuttling of polyselenides from the cathode to the anode causes dramatic capacity decay, severely impeding their practical applications. Herein, we report a combinational strategy of nitrogen and sulphur dual-doped hierarchical porous carbon with interconnected conductive polyaniline (PANI)coating to incorporate Se as stable cathodes (i-PANI@NSHPC/Se)for Na-Se batteries. Ex situ characterizations and density functional theory (DFT)calculations demonstrate that the i-PANI@NSHPC/Se cathode can provide both physical diffusion barrier and strong chemical affinity for polyselenides. In addition, the interconnected conductive polyaniline network enhances the conductivity for electrons and ions. With this strategy, the i-PANI@NSHPC/Se cathode delivered a high reversible capacity of 617 mAh g −1 after 200 cycles at 0.2C with a low capacity decay rate of 0.013% per cycle and an excellent rate capability at 20 C. Importantly, stable cycling performances were achieved with high capacities at different Se areal mass loadings (1.2, 2.3, 3.5 mg cm −2 ). This work could provide an efficient approach for developing Na-Se batteries with high active material mass loading, high rate capacity and long cycle life.
Yang, W, Yang, W, Sun, B, Di, S, Yan, K, Wang, G & Shao, G 2018, 'Mixed Lithium Oxynitride/Oxysulfide as an Interphase Protective Layer To Stabilize Lithium Anodes for High-Performance Lithium-Sulfur Batteries.', ACS applied materials & interfaces, vol. 10, no. 46, pp. 39695-39704.View/Download from: UTS OPUS or Publisher's site
Lithium metal is strongly recognized as a promising anode material for next-generation high-energy-density systems. However, unstable solid electrolyte interphase and uncontrolled lithium dendrites growth induce severe capacity decay and short cycle life accompanied by high security risks. Here, we propose a simple method for constructing an artificial solid electrolyte interphase layer on the surface of lithium metal through spontaneous reaction, where ammonium persulfate and lithium nitrate are exploited as oxidants. The satisfactory artificial protective layer with uniform and dense morphology is composed of mixed lithium compounds, mainly including Li xSO y and Li xNO y species, which could effectively stabilize the interphase between electrolyte and lithium metal anode and restrain the "shuttle effect" of polysulfides. By employing the premodified lithium metal as anodes for lithium-sulfur batteries, the resulting cells exhibit excellent cycle stability (capacity decay of 0.09% per cycle over 300 cycles at 1 C and Coulombic efficiency of over 98%) and outstanding rate capability (850.8 mAh g-1 even at 4 C). Hence, introducing a stable artificial protective layer to protect lithium anode delivers a new strategy for solving the issues related to lithium-metal batteries.