Research development on electrolytes for magnesium-ion batteries.

Magnesium-ion batteries (MIBs) are considered strong candidates for next-generation energy-storage systems owing to their high theoretical capacity, divalent nature and the natural abundancy of magnesium (Mg) resources on Earth. However, the development of MIBs has been mainly limited by the incompatibility of Mg anodes with several Mg salts and conventional organic-liquid electrolytes. Therefore, one major challenge faced by MIBs technology lies on developing safe electrolytes, which demonstrate appropriate electrochemical voltage window and compatibility with Mg anode. This review discusses the development of MIBs from the point-of-view of the electrolyte syntheses. A systematic assessment of promising electrolyte design strategies is proposed including liquid and solid-state electrolytes. Liquid-based electrolytes have been largely explored and can be categorized by solvent-type: organic solvent, aqueous solvent, and ionic-liquids. Organic-liquid electrolytes usually present high electrochemical and chemical stability but are rather dangerous, while aqueous electrolytes present high ionic conductivity and eco-friendliness but narrow electrochemical stability window. Some ionic-liquid electrolytes have proved outstanding performance but are fairly expensive. As alternative to liquid electrolytes, solid-state electrolytes are increasingly attractive to increase energy density and safety. However, improving the ionic conductivity of Mg ions in these types of electrolytes is extremely challenging. We believe that this comprehensive review will enable researchers to rapidly grasp the problems faced by electrolytes for MIBs and the electrolyte design strategies proposed to this date.

An ultrastable sodium-ion battery anode enabled by carbon-coated porous NaTi2(PO4)3 olive-like nanospheres.

NaTi2(PO4)3 (NTP) is a promising anode material for sodium-ion batteries (SIBs). It has drawn wide attention because of its stable three-dimensional NASICON-type structure, proper redox potential, and large accommodation space for Na+. However, the inherent low electronic conductivity of the phosphate framework reduces its charge transfer kinetics, thus limiting its exploitation. Therefore, this paper proposes a material with carbon-coated porous NTP olive-like nanospheres (p-NTP@C) to tackle the issues above. Based on experimental data and theoretical calculations, the porous structure of the material is found to be able to provide more active sites and shorten the Na+ diffusion distance. In addition, the carbon coating can effectively improve the electron and Na+ diffusion kinetics. As the anode material for SIBs, the p-NTP@C olive-like nanospheres exhibit a high reversible capacity (127.3 mAh g-1 at 0.1 C) and ultrastable cycling performance (84.8% capacity retention after 10,000 cycles at 5 C). Furthermore, the sodium-ion full cells, composed of p-NTP@C anode and Na3V2(PO4)2F3@carbon cathode, also deliver excellent performance (75.7% capacity retention after 1000 cycles at 1 C). In brief, this nanostructure design provides a viable approach for the future development of long-life and highly stable NASICON-type anode materials.

Electrochemical behavior of lactate dehydrogenase immobilized on "silica sol-gel/nanometre-sized tridecameric aluminum polycation" modified gold electrode and its application.

This paper reports the electrochemical behavior of lactate dehydrogenase (LDH) immobilized in the silica sol-gel film on gold electrode after adding nanometre-sized tridecameric aluminium polycation (nano-Al13, also called nanopolynuclear Al13) as a promoter. A pair of surface controlled quasi-reversible cyclic voltammetry peaks with the formal potential (E0') of 154 mV (vs. SCE) was found in the presence of nano-Al13. A potential application of the nano-Al13-LDH electrode for the determination of resorcinol and p-xylene was also investigated. The experimental results showed that both resorcinol and p-xylene inhibited LDH activity, and the calibration ranges were 5.0 x 10(-6)-3.0 x 10(-4) mol L(-1) for resorcinol and 1.0 x 10(-6)-1.0 x 10(-5) mol L(-1) for p-xylene, respectively. The nano-Al13-LDH electrode can be anticipated to be applied to environmental toxic assessments.

Direct electrochemistry of lactate dehydrogenase immobilized on silica sol-gel modified gold electrode and its application.

The direct electrochemistry of lactate dehydrogenase (LDH) immobilized in silica sol-gel film on gold electrode was investigated, and an obvious cathodic peak at about -200 mV (versus SCE) was found for the first time. The LDH-modified electrode showed a surface controlled irreversible electrode process involving a one electron transfer reaction with the charge-transfer coefficient (alpha) of 0.79 and the apparent heterogeneous electron transfer rate constant (K(s)) of 3.2 s(-1). The activated voltammetric response and decreased charge-transfer resistance of Ru(NH(3))(6)(2+/3+) on the LDH-modified electrode provided further evidence. The surface morphologies of silica sol-gel and the LDH embedded in silica sol-gel film were characterized by SEM. A potential application of the LDH-modified electrode as a biosensor for determination of lactic acid was also investigated. The calibration range of lactic acid was from 2.0 x 10(-6) to 3.0 x 10(-5) mol L(-1) and the detection limit was 8.0 x 10(-7) mol L(-1) at a signal-to-noise ratio of 3. Finally, the effect of environmental pollutant resorcinol on the direct electrochemical behavior of LDH was studied. The experimental results of voltammetry indicated that the conformation of LDH molecule was altered by the interaction between LDH and resorcinol. The modified electrode can be applied as a biomarker to study the pollution effect in the environment.