Supercapacitor electrodes assembled from meso/macroporous camphor-derived carbon sponges show highly promising performance in ac line-filtering.

The development of new battery technology that utilizes abundant electrode materials that are environmentally benign is an important area of research. To alleviate the reliance on Li‐ion batteries new energy storage mechanisms are urgently needed. To address these issues, MnO2 nanowires were investigated as a possible electrode material for use in rechargeable Al ion batteries that can operate in aqueous conditions. The use of this type of material and an aqueous electrolyte ensures safe operation as well as easy recycling of spent batteries. A potassium‐rich cryptomelane structure was presented, and a new mechanism of electrochemical energy storage was elucidated based on the intercalation and deintercalation of small‐radius Al3+ ions interchanging with larger K+ ions in the cryptomelane MnO2 nanowires, which was supported by DFT calculations. This first‐time use of a cryptomelane MnO2 cathode for an aqueous Al ion system yielded a discharge capacity of 109 mAh g−1, which indicates the potential commercial viability of rechargeable aqueous Al‐ion batteries.

Aqueous aluminum‐ion batteries are at an early development stage and there is a need to discover new electrode materials for the fabrication of high energy density devices. To address this issue, we investigate MoO3 nanowires as a possible electrode material for use in rechargeable Al‐ion batteries that can operate in aqueous conditions. We present a hexagonal structure of MoO3 microrods as an Al‐ion intercalation host material and show its first‐time use as a potential electrode for an aqueous Al‐ion battery system. This yields a discharge capacity of approximately 300 mAh g−1 for 150 cycles and around 90 % retention after 400 cycles at a current density of 3 A g−1. The utilization of this type of material and aqueous electrolytes guarantees both safety during operation and simple recycling of spent batteries.

The present study demonstrates a novel, low temperature synthetic approach by which 3-D bouquets of nickel hydroxide nitrate were processed into high surface area electrodes for supercapacitor applications. The synthesized micro-bouquets comprised randomly arrayed microporous nanoflakes (pore size: 2-6 nm) and exhibited a surface area of 150 m 2 g À1 . Morphological evolution studies were performed to elucidate how surface morphology of these electrode materials affect redox reactions and their ultimate performance as a supercapacitor. The electrodes were tested in three different electrolytes, namely lithium hydroxide, potassium hydroxide and sodium hydroxide. From the detailed electrochemical analysis, an intrinsic correlation between the capacitance, internal resistance and the surface morphology was deduced and explained on the basis of relative contributions from the faradaic properties in different electrolytes. Depending on the surface morphology and electrolyte incorporated, these nano/micro-hybrid electrodes exhibited specific mass capacitance value of as high as 1380 AE 38 F g À1 . Inductively coupled plasma-atomic emission spectroscopy was used to determine the electrode dissolution in the given electrolyte and the findings were co-related with the cycling stability. By employing this low cost electrode design, high stability (>5000 cycles with no fading) was achieved in lithium hydroxide electrolyte. Furthermore, a working model supercapacitor in a coin cell form is also shown to exhibit peak power and energy density of 3 kW kg À1 and 800 mW h kg À1 , respectively.

Li-Ion batteries (LIBs) dominate the energy storage market owing to their versatility and efficient energy storage. Also, for electric vehicle applications, batteries with better power, safety and cyclability are needed. To address the issues related to lower power density, lesser cyclability, low capacity retention, safety, cost etc. several modifications like nanostructuring, 3D and 2D architectures, doping, core shell particles, binder free electrodes, modified electrolytes and separators have been employed. Plasma technologies can reduce the number of steps and time required for the synthesis of nanoarchitectures and material modifications, hence a reduction in the cost required to produce LIBs against the high initial This article is protected by copyright. All rights reserved. 2investment required. This review paper aims at emphasising plasma enabled modification and synthesis techniques for LIB electrodes, separators, electrolytes and for recent advances like solid state and flexible batteries.

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Synthesizing metal-free, low-cost, and durable electrocatalysts that are active for the oxygen evolution reaction (OER) is essential for the development of commercial alkaline water electrolyzers. Herein, we develop a nanoconfined synthesis approach for the fabrication of a metal-free graphitic mesoporous carbon nitride (gMesoCN) electrocatalyst with a high surface area of 406 m2/g and high nitrogen content of 48%. This is achieved by a nanohard-templating approach through simple polymerization of guanidine hydrochloride (GndCl) as a single carbon–nitrogen source inside the organized mesopore channels of a mesoporous SBA15 silica nanotemplate. The produced material is characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM), which confirmed the formation of a well-ordered mesoporous carbon nitride, while analysis of the pore size distribution indicated the formation of uniformly sized pore channels of 4.56 nm. X-ray photoelectron spectroscopy (XPS) indicated that gMesoCN consisted of C and N. The metal-free gMesoCN material showed good electrocatalytic performance for the OER in alkaline medium, where a Tafel slope of 52.4 mV/dec indicated favorable OER kinetics. Significantly, the gMesoCN material demonstrates long-term durability with 98.4% retention of current density after 24 h. The reported gMesoCN material is inexpensive, environmentally friendly, and easy-to-synthesize with the potential for applicability in the field of electrocatalysis.

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