High-performance sodium-ion batteries and sodium-ion pseudocapacitors based on MoS(2) /graphene composites.

Sodium-ion energy storage, including sodium-ion batteries (NIBs) and electrochemical capacitive storage (NICs), is considered as a promising alternative to lithium-ion energy storage. It is an intriguing prospect, especially for large-scale applications, owing to its low cost and abundance. MoS2 sodiation/desodiation with Na ions is based on the conversion reaction, which is not only able to deliver higher capacity than the intercalation reaction, but can also be applied in capacitive storage owing to its typically sloping charge/discharge curves. Here, NIBs and NICs based on a graphene composite (MoS2 /G) were constructed. The enlarged d-spacing, a contribution of the graphene matrix, and the unique properties of the MoS2 /G substantially optimize Na storage behavior, by accommodating large volume changes and facilitating fast ion diffusion. MoS2 /G exhibits a stable capacity of approximately 350 mAh g(-1) over 200 cycles at 0.25 C in half cells, and delivers a capacitance of 50 F g(-1) over 2000 cycles at 1.5 C in pseudocapacitors with a wide voltage window of 0.1-2.5 V.

Feasibility of Old Bark and Wood Waste Recycling.

The pulp and paper industry leads to the formation of significant amounts of bark and wood waste (BWW), which is mostly dumped, causing negative climate and environmental impacts. This article presents an overview of methods for recycling BWW, as well as the results of assessing the resource potential of old bark waste based on physicochemical and thermal analysis. It was found that using BWW as a plant-growing substrate is challenging because it was observed that bark waste is phytotoxic. The C:N waste ratio is far from optimum; moreover, it has a low biodegradation rate (less than 0.15% per year). The calorific value content of BWW ranged from 7.7 to 18.9 MJ/kg on d.m., the ash content was from 4% to 22%, and the initial moisture content was from 60.8% to 74.9%, which allowed us to draw conclusions about the feasibility of using hydrothermal methods for their processing to obtain biofuel and for the unreasonableness of using traditional thermal methods (combustion, pyrolysis, gasification).

Mechanical force-driven growth of elongated bending TiO2 -based nanotubular materials for ultrafast rechargeable lithium ion batteries.

A stirring hydrothermal process that enables the formation of elongated bending TiO2 -based nanotubes is presented. By making use of its bending nature, the elongated TiO2 (B) nanotubular crosslinked-network anode electrode can cycle over 10 000 times in half cells while retaining a relatively high capacity (114 mA h g(-1)) at an ultra-high rate of 25 C (8.4 A g(-1)).