Effects of Various Valence Ions on an Aqueous Rechargeable Zn//Polyaniline-coated ZnMn2 O4 Battery.

Zinc corrosion and dendrite formation are the main issues which impede the performance of aqueous zinc ion batteries (ZIBs) after certain times. In this work, we systematically investigated the effects of three different valence ions (e. g., Na+ , Mg2+ , Al3+ ) as electrolyte additives on the suppression of zinc corrosion and the inhibition of dendrite growth. By combining experiments and theoretical calculations, it has been found that the existence of Na+ ions effectively suppressing the zinc dendrite growth because Na+ possessess high adsorption energy approximately -0.39 eV. Moreover, Na+ ions could lengthen the zinc dendrite formation duration up to 500 h. On the other hand, the PANI/ZMO cathode materials showed the small band gap approximately 0.097 eV, signifying that the PANI/ZMO possessed the semiconductor characteristics. Furthermore, an assembled Zn//PANI/ZMO/GNP full battery using Na+ ions as electrolyte additive displayed capacity retention of 90.2 % after 500 cycles at 0.2 A g-1 , whereas the capacity retention of the control battery using pure ZnSO4 electrolyte was only 58.2 %. This work could provide a reference for the selection of electrolyte additives in future batteries.

Rational Design Hierarchical SnS2 Uniformly Adhered to Three-Sided Carbon Active Sites to Enhance Sodium Storage.

Reducing material accumulation and designing reasonable sizes are critical strategies for increasing the rate and cycling stability of electrode materials. Herein, we presented a double-walled hollow carbon spheres (DWHCSs) loading strategy for achieving ultrafine SnS2 nanosheet adhesion by utilizing three-sided active sites of the interior/exterior carbon walls. The structure effectively shortened the electron/ion transport path, increased the effective contact between electrolyte and electrode material, and promoted ion diffusion kinetics. Furthermore, the hollow structure can adapt to the volume change of the electrode during the cycle, preventing active substances from draining. Based on the above advantages, SnS2@DWHCSs as an anode material for sodium ion batteries (SIBs) exhibited a distinguished reversible capacity of 665.7 mA h g-1 at 2 A g-1 after 1000 cycles, and a superior rate ability of 377.6 mA h g-1 at an ultrahigh rate of 10 A g-1. The outstanding electrochemical performance revealed that the structure exhibited a broad application prospect in the field of energy storage and provided a reference for the rational design of other 2D materials.

Microporous carbon coated silicon core/shell nanocomposite via in situ polymerization for advanced Li-ion battery anode material.

A microporous carbon coated core/shell Si@C nanocomposite prepared by in situ polymerization exhibits a stable capacity of over 1200 mAh g(-1) with 95.6% retention even after 40 cycles, which makes it a promising anode material for lithium ion batteries.