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Zinc oxide (ZnO) nanostructures/bacteria (Escherichia coli, E. coli) composite material is successfully prepared via carbonization process. Morphological and electrochemical properties of nanostructure were studied as function of concentration of bacteria solution. Morphological properties of the composite material were investigated by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET). The new approach of high-performance electrodes based on carbonization prepared from precursor and reductant of ZnO and bacteria resources. The ZnO nanostructures were reacted with the bacteria to introduce carbon (C) and nitrogen (N) for better electrochemical performance and an increased surface area. The bacteria doped ZnO electrode exhibited significantly enhanced specific capacitance (41 F g−1) at a discharge current density of 0.5 A g−1, and cycling stability of 55% retention after 5000 cycles. Therefore, the bacteria as electrical dopant gave higher specific capacitance and cycle stability to the other metal oxide which could be a potential candidate in commercial applications of supercapacitors.

A composite anode material is fabricated from mesoporous carbon and synthesized Li4Ti5O12 nanoflakes for application in lithium ion batteries. Li4Ti5O12 is used as a capacity contributing conductive additive because of the change in its electronic structure from insulating to metallic as it undergoes lithiation. Cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy are used to analyze the electrochemical properties of the mesporous carbon/Li4Ti5O12 nanoflakes composite material, and synergistic results have been confirmed. The composite achieves high specific capacity and excellent cyclability with a capacity stabilizing at 300 mA h g−1 after 100 cycles at a current density of 175 mA g−1 and 200 mA h g−1 after 500 more cycles at a high current density of 500 mA g−1. This research shows the applicability of using LTO as a conducting agent with significant capacity contribution as a composite material with anode materials discharged to 0.01 V for high energy storage with fast charge–discharge capability.

A novel approach of preparing high performance electrodes for supercapacitors was demonstrated by pyrolyzing the hierarchical composite prepared from organic waste and biological resources. Sponge waste was utilized as a carbon source for preparing the interconnected structured electrode materials with high porosity, and needle-like ZnO particles were directly grown on the sponge in order to effectively capture bacteria cells as well as improve the overall redox reactions. The bacteria (E. coli O157:H7) were isolated on a ZnO/sponge composite to endow electrochemically beneficial inherent nitrogen existing in bacteria, as well as to provide bio-templates with the aids of these structural and material benefits, the carbonized material prepared from the bacteria loaded on the ZnO/sponge composite showed a significantly enhanced specific capacitance of 133 F g−1 (at 0.2 A g−1) and an excellent cycle retention of 89% over long-term cycles (5000 cycles). Our strategy of utilizing recyclable and biomass-derived materials not only can effectively improve the electrochemical performances of supercapacitors but also open an innovative way to address the systemic issues underlying the carbonaceous materials used in supercapacitors.

A simple simultaneous complementary oil-water separation and water desalination system is designed using grafted glass fiber (GF) membranes. Non-fluorinated trialkoxysilanes are grafted to form superhydrophobic and superhydrophilic GF membranes, respectively. Zwitterion sulfobetaine was also synthesized and grafted on the glass fiber to make a superhydrophilic glass fiber membrane. The superwetting grafted GF membranes which are superhydrophobic had a water contact angle of 152° and high separation efficiency (>99%) for ten cycles and the superhydrophilic had an underwater oil contact angle of 156° and high separation efficiency (>98%) for ten cycles. The zwitterionic glass fiber membrane also exhibits excellent removal performance for heavy metal ions and nitrate ions from the water layer. This method is simple and scalable, and provides a versatile way for designing devices that achieve both oil/water separation and water desalination simultaneously.

Electrochemical characterization was conducted on poly(vinyl alcohol) (PVA)-ceramic composite (PVA–CC) separators for supercapacitor applications. The PVA–CC separators were fabricated by mixing various ceramic particles including aluminum oxide (Al2O3), silicon dioxide (SiO2), and titanium dioxide (TiO2) into a PVA aqueous solution. These ceramic particles help to create amorphous regions in the crystalline structure of the polymer matrix to increase the ionic conductivity of PVA. Supercapacitors were assembled using PVA–CC separators with symmetric activated carbon electrodes and electrochemical characterization showed enhanced specific capacitance, rate capability, cycle life, and ionic conductivity. Supercapacitors using the PVA–TiO2 composite separator showed particularly good electrochemical performance with a 14.4% specific capacitance increase over supercapacitors using the bare PVA separator after 1000 cycles. With regards to safety, PVA becomes plasticized when immersed in 6 M KOH aqueous solution, thus there was no appreciable loss in tear resistance when the ceramic particles were added to PVA. Thus, the enhanced electrochemical properties can be attained without reduction in safety making the addition of ceramic nanoparticles to PVA separators a cost-effective strategy for increasing the ionic conductivity of separator materials for supercapacitor applications.

Physical mixing of activated carbon (AC) and a quinone derivative, 2,5-bis (pro-2-ny-1-ylamino) cyclohexa-2,5-diene-1,4-dione (coded HBU-281) was used to design a composite electrode for supercapacitors. The process proves to be simple and cost-effective; providing better performance compared to other reported methods. The electrode properties were probed in terms of composite composition, redox behavior, specific capacitance, and cycle life. The capacitance performance of the AC electrode was enhanced due to the extra redox reaction of hydroquinone/quinone couple of HBU-281. The composites recorded higher specific capacitance and excellent cycle stability than the individual electrodes (AC or HBU-281). This excellent performance can be connected to the synergistic contribution of AC facilitating the electron distribution of HBU-281, and making pronounce its redox activity. These findings led to the conclusion that physical mixing of AC and HBU-281 can be adopted to design cheap and excellent composite electrodes for supercapacitor applications.

Liquid electrolyte consisting of 1 M LiPF 6 in ethylene carbonate (EC)/dimethyl carbonate (DMC) and 0.1 wt% benzotriazole (BzTz) is studied in LiCoO 2 //graphite battery system at room temperature. Benzotriazole addition introduces excellent electrochemical stability (5.6 V vs Li) and good ionic conductivity properties at room temperature. Also, this electrolyte shows good cycling performance and better discharge capacities at high C-rates relative to the pristine electrolyte. Furthermore, the additive allows the formation of a good solid electrolyte interphase (SEI) per cyclic voltammetry (CV) examination. These specialized properties make this liquid electrolyte ideal for high power and high voltage applications.

In this work, poly[dimethylsiloxane- co -(siloxane- g -acrylate)] (PDMS-A) and lithium-modified silica nanosalt (Li202) are used together as low-temperature electrolyte additives in lithium-ion batteries (LIBs), taking advantage of the electrochemical and interfacial stabilities due to their surface functional groups. Using these additives together improves the electrochemical stability and ionic conductivity of liquid electrolyte solution to over 5.5 V and 4 × 10 −4 S cm −1 at −20 °C, respectively. The room-temperature electrochemical performance of a conventional LIB (LiCoO 2 /graphite) is improved by the addition (e.g., initial discharge capacity of 95.9 mAh g −1 obtained after charging at 1.0 C -rate and consequent discharging at 5.0 C -rate). The low-temperature performance is also enhanced, achieving a capacity retention ratio of 63.4% after 50 cycles at −20 °C, compared to 38.7% without the additives. It is also notable that the PDMS unit commonly existing in both additives may be the main cause of the synergistic effects on the electrochemical performance due to the compatibility between PDMS-A and Li202.