obstacle to large-scale deployment. [11] From the equation, E = ½CV 2 , the energy density (E) of an electrochemical system is directly related to its specific capacitance (C) and the working voltage window (V) of SCs. [12,13] Therefore, designing an advanced SC with high capacitance as well as an enlarged voltage window is a potential strategy for the substantial improvement in its energy density property. Hybrid supercapacitors (HSCs) are a new class of SCs, which can be able to attain an improved energy density by sustaining their high-power density. These HSCs are typically composed of two different active materials, which exhibit battery-like (energy-source) and electric double-layered capacitor-like (power-source) materials, respectively. [14][15][16] Herein, battery-like materials typically exhibit high capacity performance by performing dominant reduction-oxidation (redox) reactions with electrolyte ions. [17,18] In contrast, capacitorlike materials store the charge through an adsorption/desorption process at an electrode/electrolyte interface. Therefore, developing novel battery-like materials with benefitted morphologies could greatly improve the energy density performance of SCs.Until now, distinct transition metal hydroxides/oxides, such as Ni 2 (OH) 2 CO 3 , CoMoO 4 , MnO 2 , NiAl LDHs, Co 3 O 4 , Ni(OH) 2 , etc., have been investigated as electrode materials for SCs due to their enriched redox chemistry, low cost, and multi-valence states of the involved elements. [19][20][21][22][23][24][25] However, metal oxides suffer from moderate electrochemical activity and low electrical conductivity. [26][27][28] Recently, transition metal sulfides have emerged as prominent electrode candidates for SCs owing to their two-order higher electrical conductivity than that of metal hydroxides/oxides. [29,30] Furthermore, replacing the oxygen atom in metal oxides with a low electronegativity of sulfur affords the structural deformation during intercalation/de-intercalation of foreign atoms. [31] Among the transition metal sulfides, especially nickel and cobalt sulfides, have attracted significant interest due to their several properties of high theoretical capacitance/capacity, enriched redox activity, high conductivity, multi-valence states, and natural abundance. So far, several researchers have studied the electrochemical performance of Transition bimetallic sulfides are exploited as high-capacity electrode materials in energy storage devices owing to their abundant electroactive sites and relatively high electrical conductivity compared with metal oxides. Here, an in situ conversion of metal ions into NiS 2 -CoMo 2 S 4 vertically aligned nanorod arrays on nickel foam (NS-CMS NRAs@NF) using a one-step hydrothermal technique to address the "dead-mass" limitation and multi-step preparation methods is reported. An in situ-converted NS-CMS NRAs obtained for 12 h of reaction time (NS-CMS NRAs-12 h@NF) delivers a superior areal capacity of 780 μAh cm −2 to the other NS-CMS electrodes synthesized for 6 h (543.1 μAh cm ...

Evolving cost-effective transition metal phosphides (TMPs) using general approaches for energy storage is pivotal but challenging. Besides, the absence of noble metals and high electrocatalytic activity of TMPs allow their applicability as catalysts in oxygen evolution reaction (OER). Herein, CoNiP-CoP 2 (CNP-CP) composite is in situ deposited on carbon fabric by a one-step hydrothermal technique. The CNP-CP reveals hybrid nanoarchitecture (3D-on-1D HNA), i.e., cashew fruit-like nanostructures and nanocones. The CNP-CP HNA electrode delivers higher areal capacity (82.8 𝝁Ah cm -2 ) than the other electrodes. Furthermore, a hybrid cell assembled with CNP-CP HNA shows maximum energy and power densities of 31 𝝁Wh cm -2 and 10.9 mW cm -2 , respectively. Exclusively, the hybrid cell demonstrates remarkable durability over 30 000 cycles. In situ/operando X-ray absorption near-edge structure analysis confirms the reversible changes in valency of Co and Ni elements in CNP-CP material during real-time electrochemical reactions. Besides, a quasi-solid-state device unveils its practicability by powering electronic components. Meanwhile, the CNP-CP HNA verifies its higher OER activity than the other catalysts by revealing lower overpotential (230 mV). Also, it exhibits relatively small Tafel slope (38 mV dec -1 ) and stable OER activity over 24 h. This preparation strategy may initiate the design of advanced TMP-based materials for multifunctional applications.

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Particularly, in lithium (Li)-ion battery (LIB) and supercapacitor (SC) applications, surface area and porosity properties of MOFs boost electrolyte uptake capability and shorten diffusion length. [4] Furthermore, the nanoscale voids in the MOF matrix alleviate severe volume fluctuations while performing electrochemical reactions. [5] Owing to these properties, the research community has been focused on the development of MOF-based/derived active materials to explore their applicability in the energy storage field. For instance, Shuai Nan Guo et al. prepared MOF-polyaniline sandwich-like composite using a successive oil bath method and carbonization, followed by polymerization. The as-prepared material demonstrated a maximum specific capacitance of 477 F g −1 at a current density of 1 A g −1. [6] Recently, Xueying Cao et al. synthesized the cobaltdoped Cu-MOF/Cu 2+1 O material, and investigated its SC performance. At a current density of 2 mA cm −2 , the prepared hybrid material delivered a superior specific capacitance of 518.50 F g −1. [7] In another report, Danni Shao et al. achieved a maximum specific capacitance of 414.50 F g −1 at 0.50 A g −1 from the high nitrogen (N)-contained Co-MOF nanorods. [8] Very recently, Zhuo Li et al. fabricated a 3D interconnected architecture with MOF-derived metal oxides (Fe 2 O 3 , ZnO) and N-doped carbon nanofibers. The prepared composite material was explored as an anode in LIB. At 50 mA g −1 , the composite material delivered a high initial specific capacity of 1571.40 mAh g −1. [9] In the other literature, Shiji Hao et al. employed a zeolitic imidazolate framework-67 as a template to synthesize the Co 3 S 2 nanoparticles-incorporated N-doped carbon particles for use as an anode material in LIB. The resulted material demonstrated a superior specific capacity of 950 mAh g −1 at 0.20 C. [10] Therefore, designing the MOFbased/derived electrode materials would be an inciting strategy to achieve exalted energy storage performance. On the other hand, electrode materials are the key components of energy storage systems and are predominantly responsible for energy storage performance. To date, several transition metal oxides have been synthesized and their electrochemical behavior was investigated in LIB and SC studies. [11] Compared Metal-organic frameworks (MOFs) are promising materials in diverse fields because of their constructive traits of varied structural topologies, high porosity, and high surface area. MOFs are also an ideal precursor/template to derive porous and functional morphologies. Herein, Co 3 V 2 O 8 nanohexagonal prisms are grafted on CuV 2 O 6 nanorod arrays (CuV-CoV)-grown copper foam (CF) using solution-processing methods, followed by thermal treatment. Direct preparation of active material on CF can potentially eliminate electrochemically inactive and non-conductive binders, leading to improved charge-transfer rate. Furthermore, solution-processing methods are simple and cost-effective. Owing to versatile valence states and good redox activity, the vanadium...