• Energy Research

Tin (Sn), with a theoretical capacity of 994 mAh g-1, is a promising anode material for lithium-ion batteries (LIBs). However, fundamental limitations like large volume expansion during charge-discharge cycle and confined electronic conductivity limit its practical utility. Here, we report a new material design and manufacturing method of LIB anodes using Sn and Hard Carbon (HC) architecture, which is produced by Physical Vapor Deposition (PVD). A bilayer HC/Sn anode structure is deposited on a carbon/copper sheet as a function of deposition time, temperature, and substrate heat treatment. The developed anodes are used to make cells with a lithium-ion electrolyte using a specific fabrication process. The morphology, atomic structure, conductivity, and electrochemical performance of the developed HC/Sn anodes are studied with SEM, TEM, XPS, and electrochemical techniques. At a discharge rate of 0.1C, the Snheated + HC anode performs exceptionally well, offering a capacity of 763 mAh g-1. It is noteworthy that it achieves a capacity of 342 mAh g-1 when fast charging at 5C, demonstrating exceptional rate capability. The Snheated + HC anode maintains >97 % Coulombic efficiency of its capacity after 3000 cycles at a rate of 0.1C after 3000 cycles 730.5 mAh g-1 recorded, demonstrating an impressive cycle life. The novel material design approach of the Snheated + HC anode, which has a multi-layered structure and HC acting as a barrier against volumetric expansion and improving electronic conductivity during battery cycling, is perceived as influential in uplifting anode's performance. The authors acknowledge Zawar A Qureshi and Buzaina Moosa (Qatar University) and Dr. Ramakrishnan Shanmugam (Newcastle University) who assisted in cell fabrication and cell testing.

Formate as a medium for CO2 utilisation and energy storage.

This review summaries recent development across electro-, photoelectro- and bioelectro-catalyst developments for multi-carbon products from CO2. It also explores the role of device design and operating conditions in enabling C–C bond generation.

Transition metal layered oxide materials with a general formula NaxMO2 (M = Ni, Mn, Co, Fe) are widely researched with various possible electrode configurations. Herein, O3‐type NaNi(1−x)/2Mn(1−x)/2MoxO2 (x = 0, 0.05,0.1) layered oxide cathode materials are synthesized by solid‐state reaction method, and its structural, thermal, and electrochemical performance in sodium ion battery is investigated. The structural analysis reveals that a single phase highly crystalline O3‐type cathode material with an irregular particle shape is formed. The introduction of molybdenum improves the thermal stability of cathode materials, which can be attributed to the improved TMO2 layers that provide stability to the material. The addition of Mo to Na‐layered oxide cathode materials enhances electrochemical performance. The developed cathode materials, the NaNi0.475Mn0.475Mo0.05O2, exhibit excellent specific discharge capacity (≈154 mAh g−1) at C/20 rate, (an increase of ≈20% when compared to the NaNi0.5Mn0.5O2) which can be attributed to the increased capacitance effect by the addition of Mo. The electrochemical impedance spectroscopy study reveals that the diffusion of Na+ into/from the host structure is rapid during the first cycle and then gradually reduces with subsequent cycling due to the formation of the solid electrolyte interface layer, which hinders Na+ migration. This has a potential effect on the improved electrochemical performance of the material.

Rapid industrialization is causing a serious threat for the environment. Therefore, this research was aimed in developing ceramic cobalt ferrite (CoFe2O4) nanocomposite photocatalyst coated with coal fly ash (CFA-CoFe2O4) using facile hydrothermal synthesis route and their applications against methylene blue. The pristine cobalt ferrite photocatalyst was also prepared, characterized, and applied for efficiency comparison. Prepared photocatalyst were characterized by X-ray diffraction (XRD), fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Optical response of catalysts was check using photoluminescence spectroscopy (PL). pH drift method was used for the surface charge characteristics of the material under acidic and basic conditions of solution pH. The photocatalytic degradation potential of all the materials were determined under ultra-violet irradiations. The influencing reaction parameters like pH, catalyst dose, oxidant dose, dye concentration, and irradiation time, were sequentially optimized to obtain best suited conditions. The 99% degradation of 10 ppm methylene blue was achieved within 60 min of reaction time under pH = 5 and 7, catalyst dose = 10 and 12 mg/100 mL, oxidant = 12 mM and 5 mM for cobalt ferrite and CFA-CoFe2O4 photocatalysts, respectively. Afterwards, the radical scavenging experiments were conducted to find out the effective radical scavengers (˙OH, h+, and e-) in photocatalytic degradation process. The kinetic study of the process was done by applying 1st order, 2nd order, and BMG models. Statistical assessment of interaction effect among experimental variables was achieved using response surface methodology (RSM).

In this work, phase pure and highly crystalline O3-type layered oxide material (Na1Ni0.33Mn0.33Fe0.33O2-NNMF) was developed using; (i) a conventional solid-state synthesis route and (ii) a facile microwave-assisted sol–gel technique. A comparison of structural, thermal, and electrochemical properties is presented to elucidate the usefulness of the microwave-assisted sol–gel synthesis technique. A remarkable reduction in the sintering process time is noticed in the microwave-assisted sol–gel synthesis technique without compromising on the structural, thermal and electrochemical properties when compared to the conventional solid-state synthesis route confirming its decent cost-effectiveness. It is further noticed that NNMF developed through microwave-assisted sol–gel synthesis technique demonstrates superior thermal stability and comparable electrochemical performance as compared to the same material produced through the conventional sintering process. The decent electrochemical properties induced in NNMF during the microwave-assisted sol–gel synthesis technique can be attributed to the efficient diffusion of Na+ ions into/from the host structure during the intercalation/de-intercalation process as indicated by the high value of sodium diffusion coefficient (1 × 109-3.58 × 109m2s−1). The Potentiostatic Intermittent Titration Technique (PITT) analysis confirms single-phase Na+ intercalation/deintercalation in the host structure, regardless of the synthesis process. Finally, EIS analysis confirms the capacity fading of the developed materials during the cycling process is essentially due to an increase in the resistance with the increasing number of cycles due to the gradual thickening of formed SEI layer. The microwave-assisted sol–gel synthesis technique can be effectively employed for the production of many families of cathode materials at competitive cost facilitating their commercialization.

A novel framework, integrating dynamic simulation (DS), life cycle assessment (LCA) and techno-economic assessment (TEA) of a bioelectrochemical system (BES), has been developed to study for the first time wastewater treatment by removal of chemical oxygen demand (COD) by oxidation in anode and thereby harvesting electron and proton for carbon dioxide reduction reaction or reuse to produce products in cathode. Increases in initial COD and applied potential increase COD removal and production (in this case formic acid) rates. DS correlations are used in LCA and TEA for holistic performance analyses. The cost of production of HCOOH is €0.015-0.005 g-1 for its production rate of 0.094-0.26 kg yr-1 and a COD removal rate of 0.038-0.106 kg yr-1. The life cycle (LC) benefits by avoiding fossil-based formic acid production (93%) and electricity for wastewater treatment (12%) outweigh LC costs of operation and assemblage of BES (-5%), giving a net 61MJkg-1 HCOOH saving.