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Lithium‐ion capacitors (LICs), with their higher energy density at high power capability, stand out as the future generation of energy‐storage devices. Herein, the nanocomposite of Ti3C2Tx MXene with Nb2Mo3O14 is prepared by a one‐step hydrothermal method and studied as an electrode material for LIC. The as‐fabricated composite MXene niobium molybdenum oxide (MXNMO) achieves a high reversible capacity of 205 mAh g−1 at 100 mA g−1 current density with outstanding cyclability. Further, asymmetric LIC full‐cell device composed of MXNMO anode with supercapacitor grade activated carbon as a cathode delivers an energy density of 37.8 Wh kg−1 (0.25 A g−1) and a higher power density of 4244 W kg−1 (5 A g−1) along with the excellent durability showing 85% capacitance retention over 4000 cycles at 0.5 A g−1. [ABSTRACT FROM AUTHOR]

Three different compositions of NiCo2S4 (NCS) materials were prepared using three solvents, named NCS HTDI (hydrothermal in DI water), NCS STEG (solvothermal in ethylene glycol), and a novel carbon‐encapsulated NCS STFA (solvothermal in formamide). The structural and morphological properties of the prepared NCS HTDI, NCS STEG, and NCS HTDI materials were analyzed using various physical characterization techniques. As prepared, NCS materials were tested as an electrode for supercapacitor (SC) application using a 3‐electrode system in a basic electrolyte (3 M KOH). NCS HTDI exhibits a specific capacitance of 2536 F g−1, NCS STEG shows 1355 F g−1, and NCS STFA shows 1178 F g−1 at an input current density of 1 A g−1. The SBN‐PSC material is utilized as a counter electrode in the NCS STFA || SBN‐PSC‐based asymmetric SC device. The device exhibits exceptionally superior electrochemical performance with a specific capacitance of 172 F g−1 at 10 A g−1 input current density and 97% capacity retention after 5000 cycles in a voltage window of 1.6 V. The results confirm the superiority of NCS STFA||SBN‐PSC deviceas an excellent high‐energy and high‐power SC. [ABSTRACT FROM AUTHOR]

A unique approach has been applied for the synthesis of 1D boron carbon nitride nanotubes (BCN-NTs) using MnO2 nanowires as templates. BCN-NTs have been evaluated in Na-ion batteries, Li-ion batteries, and supercapacitors as electrode material and exhibited excellent and stable electrochemical performance. BCN-NTs as an anode for Na-ion battery has been shown to be highly stable up to 3000 cycles with capacity retention of 95 mAh g-1, at a high current density of 1 A g-1. In the case of the Li-ion battery, these BCN-NTs show a specific capacity of 563 mAh g-1 at a current density of 50 mA g-1. Finally, when used as an electrode for a supercapacitor, BCN-NTs display a specific capacity of 221 F g-1 at a current density of 3 A g-1 and 168 F g-1 even at a very high current density of 30 A g-1 exemplifying the excellent rate performance. The multifunctionality and stable performance of BCN-NTs among various electrochemical energy storage systems highlight the robustness of the material and make it an excellent candidate for scalable production and commercialization. [ABSTRACT FROM AUTHOR]

Three different compositions of NiCo 2 S 4 (NCS) materials were prepared using three solvents, named NCS HTDI (hydrothermal in DI water), NCS STEG (solvothermal in ethylene glycol), and a novel carbon-encapsulated NCS STFA (solvothermal in formamide). The structural and morphological properties of the prepared NCS HTDI, NCS STEG, and NCS HTDI materials were analyzed using various physical characterization techniques. As prepared, NCS materials were tested as an electrode for supercapacitor (SC) application using a 3-electrode system in a basic electrolyte (3 M KOH). NCS HTDI exhibits a specific capacitance of 2536 F g -1 , NCS STEG shows 1355 F g -1 , and NCS STFA shows 1178 F g -1 at an input current density of 1 A g -1 . The SBN-PSC material is utilized as a counter electrode in the NCS STFA || SBN-PSC-based asymmetric SC device. The device exhibits exceptionally superior electrochemical performance with a specific capacitance of 172 F g -1 at 10 A g -1 input current density and 97% capacity retention after 5000 cycles in a voltage window of 1.6 V. The results confirm the superiority of NCS STFA||SBN-PSC deviceas an excellent high-energy and high-power SC., (© 2023 Wiley-VCH GmbH.)

Conversion-type anode materials have been intensely studied for application in Li-ion batteries (LIBs) due to their potentially higher capacities than current graphite-based anodes. This work reports the development of a high-capacity and stable anode from a nanocomposite of N and S co-doped carbon spheres (NSCSs) with Co 3 O 4 (NSCS-Co 3 O 4 ). A hydrothermal reaction of saccharose with l-cysteine was carried out, followed by its carbonization. CSs when used as supports for conversion-type materials provide efficient electron/ion transfer channels, enhancing the overall electrochemical performance of the electrodes. Additionally, the heteroatoms doped in a carbon matrix alter the electronic properties, often increasing the reactivity of the carbon surface, and they are reported to be effective for anchoring metal oxide nanoparticles. Consequently, the NSCS-Co 3 O 4 nanocomposites developed in this work exhibit enhanced and stable reversible specific capacity over several cycles. Stable cycling behavior was observed at 1 A g -1 with 1285 mA h g -1 of specific capacity retained after 350 cycles along with more than 99% of coulombic efficiency. This material shows excellent rate capability with a specific capacity of 745 mA h g -1 retained even at a high current density of 5 A g -1 . Detailed DFT-based calculations revealed the role of doped supports in controlling the volume expansion upon lithiation., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)