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β-Mn 2 V 2 O 7 , for the first time, is synthesized by a simple and cost-effective zeolitic imidazolate framework precipitation technique using water as the sole solvent and reported for excellent electrochemical Li storage properties. The anode delivers specific capacities of 868 and 751 mA h g −1 at rates of 500 and 2000 mA g −1 after 180 and 400 cycles, respectively.

The present study reports on the direct synthesis of LiFePO 4 nanoparticles and graphene nanosheets to form a composite cathode (LFP/GNs) in a one-step microwave-assisted polyol reaction. The polyol reaction induced by microwave irradiation for a few minutes produces nanocrystalline LFP and graphene nanosheets simultaneously from lithium, iron and phosphorus and carbon (5 wt% of graphite oxide) sources, respectively, used as starting precursors. Powder X-ray diffraction (XRD), electron microscopy, and atomic force microscopy (AFM) studies on microwave-reacted sample obtained using just graphite oxide confirms the formation of graphene nanosheets separately. Whereas, electron microscopy studies on the LFP/GNs composite reveals that olivine nanoparticles of average sizes ranging between 5 and 20 nm are well-dispersed on the graphene nanosheets. Electrochemical measurements reveal that the LiFePO 4 /GNs nanocomposite cathodes registered enhanced discharge capacities (79 and 108 mAh g −1 for the as-prepared and annealed composite cathodes, respectively) at 32 C rates with good capacity retention capabilities. The AC impedance measurements confirm that the enhanced cathode properties of the LFP/GNs nanocomposite are ascribed to the improved electronic conductivity of the graphene nanosheets and the nano-sized particles. The slightly better electrochemical properties of the annealed LFP/GNs are attributed to its higher crystallinity.

Energy storage devices remain critical to meet the increasing demands of the modern society. Rechargeable lithium ion batteries (LIBs) are a crucial finding in this century to compensate the energy demand in the present day. As device performance is intimately correlated with the material properties, production of functional energy storage nanomaterials endowed with exceptional physico-chemical properties in view of their particle-size confinement has become critically significant. Low- or moderate-temperature synthetic strategies that are versatile, easily scalable, and efficiently produce size-tuned and efficient materials are essential. In the recent past, combustion-based synthetic process has emerged as one of the promising strategies for developing customized energy storage nanomaterials due to rapid synthesis and ease of preparations in a large scale, etc. In the present review, the advancements in the design and chemistry of these strategies in developing a wide range of high voltage cathode materials for LIBs have been discussed. Among the various combustion techniques, this study will focus mainly on solution combustion, sol-gel based combustion and polyol-based pyro-synthesis. The versatility of these processes to provide tailored particle morphologies and particle sizes at the nanoscale and their effects on the material performance in various applications, particularly in energy storage, is also discussed.

In the present study, a nanorod-type α-MnO2 cathode is prepared by a facile hydrothermal method for rechargeable aqueous zinc-ion battery (ZIB) applications. Electron microscopy studies reveal rod shaped particles with approximately 20 nm of width and 200 nm of length. When tested for aqueous ZIBs, the α-MnO2 nanorod cathode exhibits an initial discharge capacity of 233 mA h/g at a current density of 83 mA/g with nearly 100% Coulombic efficiencies under prolonged cycling. Besides, the prepared cathode demonstrates decent rate capabilities at higher current densities (43.33 and 31.48 mA h/g at 1333 and 1666 mA/g, respectively). Ex-situ synchrotron XAS investigations clearly establish the reversibility of electrochemical Zn-insertion into the α-MnO2 nanorod cathode. The analyses also reveal that the host α-MnO2 structure demonstrates considerable structural stability during Zn-insertion/extraction. Further, a combination of ex-situ synchrotron XRD studies, visualization and pattern-fitting software programs not only confirm electrochemical Zn-insertion into the host α-MnO2 structure but also suggest that the unit cell volume of the [2×2] tunnels in the α-MnO2 host expands by approximately 3.12% during Zn-insertion. The present study thus paves the way for further development of eco-friendly ZIB as an ideal energy storage system due to its excellent safety and reliability.

An efficient synthesis is used for the first time to prepare CuO/reduced graphene oxide nanocomposite anode materials for lithium ion batteries. Initially, copper oxide (CuO) nanoparticles are synthesized via a simple, facile and inexpensive microwave-assisted method within short reaction times (