Search

Sodium molybdate (Na−Mo−O) wrapped by graphene oxide (GO) composites have been prepared via a simple in‐situ precipitation method at room temperature. The composites are mainly constructed with one dimension (1D) ultra‐long sodium molybdate nanorods, which are wrapped by the flexible GO. The introduction of GO is expected to not merely provide more active sites for lithium‐ions storage, but also improve the charge transfer rate of the electrode. The testing electrochemical performances corroborated the standpoint: The Na−Mo−O/GO composites delivers specific capacities of 718 mAh g−1 after 100 cycles at 100 mA g−1, and 570 mAh g−1 after 500 cycles at a high rate of 500 mA g−1; for comparison, the bare Na−Mo−O nanorod shows a severe capacity decay, which deliver only 332 mAh g−1 after 100 cycles at 100 mA g−1. In view of the cost‐efficient and less time‐consuming in synthesis, and one‐step preparation without further treatment, these Na−Mo−O nanorods/GO composites present potential and prospective anodes for LIBs. [ABSTRACT FROM AUTHOR]

Hollow structures of transition metal sulfides, could be promising for energy devices such as hybrid supercapacitors, lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Specially, mixed transition metal sulfides, benefiting from synergetic effects of the multiple metal species, have shown significant advance in the electrochemical performances of LIBs. Whereas, there is no report on exploring them as the electrode materials for sodium ion batteries (SIBs). Herein, we reported the successful fabrication of Zn0.33Co0.67S hollow microspheres with well‐defined voids via a novel sulfidation into ZnCo2‐glycolate solid microspheres and employed them as the electrodes in rechargeable secondary batteries like LIBs and SIBs. Specifically, in LIB testing, the Zn0.33Co0.67S hollow microsphere electrodes delivered a reversible capacity of 540 mA h g–1 at the current density of 500 mA g–1 over 200 cycles. Interestingly, as the pioneering anode among mixed transition sulfides in SIBs, Zn0.33Co0.67S hollow microsphere electrodes still stored Na+ as high as 420 mA h g–1 at 500 mA g–1 over 50 sodiation/desodiation repeating cycles. [ABSTRACT FROM AUTHOR]

The main issues of lithium–sulfur (Li–S) batteries, including the insulating properties of electrode materials and the dissolution of lithium polysulfides into electrolytes, hinder their further development. Encapsulating S with a conductive agent is considered as an effective way to address these issues. The electrical conductivity of the electrode is substantially improved by the addition of a conductive agent. Furthermore, the polysulfide dissolution is also effectively suppressed by the physical/chemical confinement of the additives. An exploration of new encapsulation agents for the S cathode–hierarchical porous carbon derived from a peanut hull is reported. Such structures comprise the 3D interconnected network carbon and abundant meso/micropores, which significantly improve the electronic conductivity and effectively suppress the polysulfide dissolution. The high S loading, long lifespan, and great rate capability empower such a strategy to be an effective way to push the Li–S battery to further development. An exploration of a new encapsulation agent for S cathode is reported, hierarchical porous carbon (HPC) derived from peanut hull, which could significantly improve the electronic conductivity and effectively suppress the polysulfide dissolution. The high S loading, the long lifespan, and great rate capability empower such a strategy to be an effective way to push the Li–S batteries forward in development. [ABSTRACT FROM AUTHOR]