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Zinc metal is widely used as an anode in various aqueous systems. However, zinc anode suffers from the dendrite formation on the surface upon cycling leading to a poor cyclability of a cell and its termination due to short circuit. In this work, the effect of tetrapropylammonium hydroxide (TPAH) was studied as an electrolyte additive for aqueous Zn//ZnCl2 + LiCl//LiFePO4 battery. TPAH additive prolongs the battery cycle life depending on its concentration (0.01–0.1 M). The better capacity retention over 350 cycles was observed for a symmetrical Zn//ZnCl2 + LiCl//Zn cell with 0.05 M TPAH whereas without additives the cell worked for only 110 cycles. The mechanism of TPAH influence on capacity retention is proposed based on the results of SEM and XRD analysis of the Zn anode and FTIR and NMR studies of the electrolyte. The XRD patterns of the negative electrode of the cell with TPAH indicates that zinc was preferentially deposited in a highly oriented (002) direction, which is more resistant against dendrite formation. These differences in deposited structure of Zn dendrites were confirmed by SEM images as well. FTIR and NMR spectra showed that TPAH decomposes to propylamine (RnN+H) and propene during cycling. TPAH also has an effect on the size and uniform distribution of Zn growth sides.

This paper reports the synthesis of the silica (SiO2) from Kyzylorda rice husk (RH) and investigation of its electrochemical behaviour as an anode material for the lithium-ion battery. Rice husk, considered as agricultural waste material, contains a substantial amount of amorphous silica, carbon, and minor other mineral composition, which have potential industrial and scientific applications. Due to the high theoretical capacity of silicon (4200 mAh g-1) and silicon dioxide (1965 mAh g-1), Si-containing compounds are considered as a promising candidate for a new generation of anode materials for lithium-ion batteries. In this work, the technology of amorphous SiO2 extraction from Kyzylorda region rice husk is developed. The silica powder was obtained by burning the rice husk and treating the obtained ash with the sodium hydroxide and hydrochloric acid. The extracted SiO2 and intermediate products were studied by the SEM, XRD, XRF, XPS, TGA in comparison with commercial silica. The RH of the Kyzylorda region has 12% of Si. The electrochemical characteristics of assembled coin cell type battery were tested by using cyclic voltammetry and galvanostatic charge/discharge cycling. Results show that silica synthesized from agriculture waste has the same performance as commercial analog. The initial discharge capacity of the battery with synthesized silicon dioxide was 1049 mAhg-1. The reversible discharge capacity in the second and subsequent cycles is about 438 mAhg-1.

The free‐standing cobalt phosphides‐based composite nanofiber mats with different compositions (CoyP/C, CoxP/Co3(PO4)2/C, where 2>x>y>1) were synthesized by electrospinning with heat treatments and applied as multi‐functional interlayers for lithium‐sulfur batteries. The polysulfide confining ability of the interlayers was evaluated by a static polysulfide adsorption test and an electrochemical conversion test using symmetric cells. The CoxP/Co3(PO4)2/C exhibited better catalytic performance for converting polysulfides, owing to the combination of CoxP with Co3(PO4)2 and P‐doped carbon. As a result, the lithium‐sulfur cell with this interlayer delivered a high initial discharge capacity of 1483 mAh g−1 at 0.1 C, retaining 705 mAh g−1 after 200 cycles at 0.5 C with 100 % Coulombic efficiency. The polysulfide trapping by the interlayer was further elucidated from the results of its ex situ characterizations after discharge and charge processes at different cycles in lithium‐sulfur cells.

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