Search

Herein, we explore a new redox donor–acceptor conjugated microporous polymer (AQ‐CMP) by utilizing anthraquinone and benzene as linkers via C‐C linkages and demonstrate the first use of CMP as ultralong‐lived anodes for rechargeable air batteries. AQ‐CMP features an interconnected octupole network, which affords not only favorable electronic structure for enhanced electron transport and n‐doping activity compared to linear counterpart, but also high density of active sites for maximizing the formula‐weight‐based redox capability. This coupled with highly cross‐linked and porous structure endows AQ‐CMP with a specific capacity of 202 mAh g−1 (96 % of theoretical capacity) at 2 Ag−1 and ≈100 % capacity retention over 60000 charge/discharge cycles. The assembled CMP‐air full cell shows a stable and high capacity with full capacity recovery after only refreshing cathodes, while the decoupled electrolyte and cathode design boosts the discharge voltage and voltage efficiency to ≈1 V and 87.5 %. [ABSTRACT FROM AUTHOR]

A sustainable and easy method for the fabrication of a composite of ultra-fine few-layer MoS2 structures embedded on N,P-co-doped bio-carbon (MoS2-N/P-C) was developed by using natural chlorella as an adsorbent and reactor. This MoS2-N/P-C composite was easily synthesized by carrying out a biosorption of chlorella and a subsequent calcination process. This bio-carbon made from chlorella acted as a nanoreactor to prevent the MoS2 nanoparticles from agglomerating with each other during the calcination process. Besides, the N,P-codoped bio-carbon contributed to the relatively high conductivity and surface wettability of this composite and accommodated the large radius of Na+. When used as an anode for sodium ion batteries, it showed significant superiority with a high rate and long-duration cycling performance, evidenced by a measured capacity of 175 mA h g−1 after 2000 cycles at 5 A g−1. [ABSTRACT FROM AUTHOR]

Rational fabrication of anode electrodes for sodium-ion batteries remains a challenge due to the problem of sluggish Na+ diffusion kinetics, large volume expansion etc. Significant efforts, such as fabricating carbon composites and novel nanostructures, have been devoted to the development of anode materials. Herein, an ultra-small few-layer MoS2 nanostructure confined on a hierarchical porous carbon fiber composite was synthesized through the nanocasting route using a novel hierarchical porous carbon fiber as the template. As an anode material, the composite displays outstanding electrochemical performance for sodium-ion batteries. For instance, it delivers high reversible capacities (491 mA h g−1 after 50 cycles at 0.1 A g−1), high rate performance (387 mA h g−1 at 2 A g−1) and long-term cycling stability (234 mA h g−1 at 1 A g−1 after 3000 cycles). Note that it shows one of the best long-term cycling properties reported to date for MoS2-based anode materials for sodium-ion batteries. This regulation strategy may offer new insights into the fabrication of high-performance anode materials for sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Constructing nanocomposites uniformly anchored on conductive matrix has been regarded as a valid method to improve electrochemical performance. In this work, the SnS 2 /PCF composite was fabricated by a feasible nanocasting strategy, and its microstructure was that the SnS 2 nanosheets anchored on porous carbon fibers, which can effectively solve the problem of the poor conductivity and large volume fluctuation of SnS 2 during charge/discharge process. Thus, when employed as anode of sodium-ion batteries, the SnS 2 /PCF composite delivered a high reversible capacity of 425 mA h g−1 after 140 cycles at 0.2 A g−1 and superior rate performance (360 mA h g−1 at 2 A g−1), suggesting the SnS 2 /PCF is a promising anode material for SIBs. The SnS 2 nanosheets anchored on porous carbon fibers is fabricated by a facile nanocasting strategy (denoted as SnS 2 /PCF). When used as an anode material for SIBs, it delivers a high specific capacity of 425 mA h g−1 after 140 cycles at a current density of 0.2 A g−1 and superior rate performance (360 mA h g−1 at 2.0 A g−1). Unlabelled Image • The SnS 2 /PCF composite was obtained via facile nanocasting strategy. • The SnS 2 nanosheets uniformly anchored on PCF. • The composite shows high reversible capacity of 425 mA h g−1 (0.2 A g−1, 140 cycles). • The composite exhibits high rate capacity of 360 mA h g−1 at 2 A g−1. [ABSTRACT FROM AUTHOR]

The optimized VN-2 composite exhibits an impressive high-rate capacity and ultra-long lifespan for zinc-ion batteries in all-climate conditions (-15–50 °C) achieved by the Zn2+ intercalation and conversion storage mechanism. [Display omitted] • The VN shows a high capacity of 272 mAh g−1 after 7000 cycles at 5 A g−1. • The ex-situ results disclose the Zn2+ intercalation and conversion storage mechanism. • It shows remarkable performance for AZIBs in all-climate conditions (-15–50 °C). Rechargeable aqueous zinc-ion batteries have great promise for becoming next-generation storage systems, although the irreversible intercalation of Zn2+ and sluggish reaction kinetics impede their wide application. Therefore, it is urgent to develop highly reversible zinc-ion batteries. In this work, we modulate the morphology of vanadium nitride (VN) with different molar amounts of cetyltrimethylammonium bromide (CTAB). The optimal electrode has porous architecture and excellent electrical conductivity, which can alleviate volume expansion/contraction and allow for fast ion transmission during the Zn2+ storage process. Furthermore, the CTAB-modified VN cathode undergoes a phase transition that provides a better framework for vanadium oxide (VO x). With the same mass of VN and VO x , VN provides more active material after phase conversion due to the molar mass of the N atom being less than that of the O atom, thus increasing the capacity. As expected, the cathode displays an excellent electrochemical performance of 272 mAh g−1 at 5 A g−1, high cycling stability up to 7000 cycles, and excellent performance over a wide temperature range. This discovery creates new possibilities for the development of high-performance multivalent ion aqueous cathodes with rapid reaction mechanisms. [ABSTRACT FROM AUTHOR]