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Item Enhanced Electrochemical Performance of Low-Content Graphene Oxide in Porous Co3O4 Microsheets for Dual Applications of Lithium-Ion Battery Anode and Lithium-Ion Capacitor(Springer, 2024) Lakshmi Sagar, G.; Brijesh, K.; Mukesh, P.; Amudha, A.; Bhat, K.S.; Nagaraja, H.S.The enhancement of electrochemical performance in lithium-ion battery (LIB) anode materials through nanostructures is of paramount importance, facilitated by the synergistic integration of these unique architectures with active materials, which increases the availability of active sites and decreases the diffusion path for lithium ions. In this investigation, we successfully synthesized cobalt oxide (Co3O4) microsheets composed of small nanoparticles (measuring 28–33 nm), employing a straightforward hydrothermal process followed by annealing. Furthermore, to enhance the composite’s ability to endure volume changes and increase its electrical conductivity, we created a Co3O4/reduced graphene oxide (rGO) composite embedding a judicious amount of graphene oxide (GO). This engineered composite exhibited remarkable specific discharge capacity of 1081 mAh g−1 at 100 mA g−1, a substantial improvement over the pristine material’s capacity of 718 mAh g−1. The composite demonstrated reduced irreversible capacity loss relative to the pristine counterpart and approached a reversible capacity of nearly 99%. Even after 400 cycles under the demanding conditions of high current density of 500 mA g−1, the composite managed to retain 81% of its initial capacity, underscoring its exceptional cycling stability. Moreover, the application of the Co3O4/rGO//carbon black (CB) assembly in lithium-ion capacitors (LIC) yielded notable energy density of 15.6 Wh kg−1 at elevated power density of 1007 W kg−1. These LIC devices demonstrated robust cyclic stability across extended cycles, sustaining 56% of their initial capacity after 2000 cycles while operating at a current density of 2 A g−1. Graphical Abstract: [Figure not available: see fulltext.]. © 2024, The Minerals, Metals & Materials Society.Item Impact of copper doping on the electrochemical response of MnSe2 as anode for lithium-ion battery(Springer, 2024) Mukesh, P.; Lakshmi Sagar, G.; Brijesh, K.; Kumawat, S.; Hegde, A.; Kumar, A.; Nagaraja, H.S.Transition Metal Chalcogenides (TMC), due to their unique physicochemical properties, are studied in various fields and have potent applications in energy storage applications. This work is based on the synthesis and characterization of copper-doped manganese di-selenide and the effect of its doping on electrochemical performance as anode material for lithium-ion battery applications using the solvothermal method. The characterization techniques used are X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, XPS, UV–visible absorption spectroscopy, and electrochemical analysis. The XRD data confirms the formation of MnSe2 exhibiting Cubic crystal geometry. The FESEM images show the micro-cube-like structure with agglomerated nanocluster nanostructures on the surface with a dimension of 100–200 nm. The doping of the copper has decreased the band gap of the MnSe2, as studied by the UV–visible absorption spectrum. The electrochemical performance is analyzed as anode material for lithium-ion batteries. The charge/discharge measurements show a specific capacity of 706 mAh g−1 as the initial discharge capacity and 336 mAh g−1 as the initial charge capacity at 0.1 A g−1 current density. Meanwhile, 3% Copper-doped MnSe2 showed a better specific capacity of 878 mAh g−1 as the initial discharge capacity and 461 mAh g−1 as the initial charge capacity at 0.1 A g−1 current density. Cyclic stability, rate capability, and electrochemical impedance spectroscopy were performed, and it shows that 3% copper-doped MnSe2 has good stability and better conductivity and charge kinetics, indicating copper doping has enhanced the electrochemical performance of pristine MnSe2. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Item Synergistic boost in Fe3O4 anode performance for li-ion batteries via Zn and Cu double doping and multi-walled carbon nanotube composite integration(Elsevier B.V., 2024) Kumar, A.; Mukesh, P.; Lakshmi Sagar, G.; Hegde, A.; Nagaraja, H.S.In this study, a novel nanocomposite material comprising pure Fe3O4 (FO), doped Zn0.5Cu0.5Fe2O4-3 (ZCFO-3), and Zn0.5Cu0.5Fe2O4-3@ Multi-walled carbon nanotube (ZCFO-3@MWCNT) nanocomposite material is carefully prepared using a simple one-step hydrothermal process. Comprehensive surface and morphological analysis are conducted using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and High-resolution transmission electron microscopy (HRTEM), while compositional studies are investigated through Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrochemical performance is fully analyzed through Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), rate capability tests, discharge/charge capacity, and cyclic stability evaluations. Among these three nanomaterials, ZCFO-3@MWCNT nanocomposite at 100 mA g−1 current density reveals the best performance, with a discharge capacity of 1974 mAh g–1, ZCFO-3 and FO reveal 1340 mAh g–1 and 1317 mAh g–1 respectively. After 800 cycles at 500 mA g−1 current density, ZCFO-3@MWCNT stays strong with a discharge capacity of 646 mAh g–1, while ZCFO-3 manages only 362 mAh g–1 and FO only 111 mAh g–1. After 1200 cycles at 500 mA g−1, the nanocomposite still delivers 518 mAh g–1. This study suggests that ZCFO-3@MWCNT could be a promising anode material for lithium-ion batteries. © 2024 Elsevier B.V.