Development of an Amorphous Nickel Boride/Manganese Molybdate Heterostructure as an Efficient Electrode Material for a High-Performance Asymmetric Supercapacitor

Abstract

The exploration of heterostructure materials with unique electronic properties is considered a desirable platform for fabricating electrode/surface interface relationships for constructing asymmetric supercapacitors (ASCs) with high energy density. In this work, a heterostructure based on amorphous nickel boride (Ni X B) and crystalline square bar-like manganese molybdate (MnMoO4) was prepared by a simple synthesis strategy. The formation of the Ni X B/MnMoO4 hybrid was confirmed by powder X-ray diffraction (p-XRD), field emission scanning electron microscopy (FE-SEM), field-emission transmission electron microscopy (FE-TEM), Brunauer–Emmett–Teller (BET), Raman, and X-ray photoelectron spectroscopy (XPS). In this hybrid system (Ni X B/MnMoO4), the intact combination of Ni X B and MnMoO4 leads to a large surface area with open porous channels and abundant crystalline/amorphous interfaces with a tunable electronic structure. This Ni X B/MnMoO4 hybrid shows high specific capacitance (587.4 F g–1) at 1 A g–1, and it even retains a capacitance of 442.2 F g–1 at 10 A g–1, indicating superior electrochemical performance. The fabricated Ni X B/MnMoO4 hybrid electrode also exhibited an excellent capacity retention of 124.4% (10000 cycles) and a Coulombic efficiency of 99.8% at a current density of 10 A g–1. In addition, the ASC device (Ni X B/MnMoO4//activated carbon) achieved a specific capacitance of 104 F g–1 at 1 A g–1 and delivered a high energy density of 32.5 Wh.kg–1 with a power density of 750 W·kg–1. This exceptional electrochemical behavior is due to the ordered porous architecture and the strong synergistic effect of Ni X B and MnMoO4, which enhances the accessibility and adsorption of OH– ions that improve electron transport. Moreover, the Ni X B/MnMoO4//AC device exhibits excellent cyclic stability with a retention of 83.4% of the original capacitance after 10000 cycles, which is due to the heterojunction layer between Ni X B and MnMoO4 that can improve the surface wettability without causing structural changes. Our results show that the metal boride/molybdate-based heterostructure is a new category of high-performance and promising material for the growth of advanced energy storage devices.

Tailoring the Perovskite Structure to Acquire an Inorganic La2NiCrO6 Double Perovskite as an Efficient Energy Storage Application by Varying Molar Concentrations of Citric Acid

“…The increase in capacity value is due to the increase in surface wettability of AC and the synergic effect between both porous electrode materials during the charge–discharge cycle. Due to that, the asymmetric device (LNC3@Ni-foam//AC@Ni-foam) exhibits an increment in specific capacity . After 6000 cycles, the specific capacity remains the same for long cycles; hence, this device is suitable for long charge–discharge applications.…”

“…Due to that, the asymmetric device (LNC3@ Ni-foam//AC@Ni-foam) exhibits an increment in specific capacity. 51 After 6000 cycles, the specific capacity remains the same for long cycles; hence, this device is suitable for long charge−discharge applications. The specific capacity value is maintained at 97.1% after 10,000 cycles at the current density of 10 A g −1 .…”

Constructing Crystalline NiCoP@Amorphous Nickel–Cobalt Boride Core–Shell Nanospheres with Enhanced Rate Capability for Aqueous Supercapacitors and Rechargeable Zn-Based Batteries

“…Furthermore, the ASC exhibits a specific capacity retention ratio of 59.4%, after 20 000 cycles at 10 A g −1 (Figure 6h). In Figure 6i, the NiCoP@NiCo−B-70// AC ASC reaches an energy density of 40.8 Wh kg −1 at a power density of 400.0 W kg −1 , and the energy density of 21.3 Wh kg −1 can be retained even at a maximum power density of 4000.0 W kg −1 , which outperforms other reported asymmetric energy storage devices, such as Ni x B/MnMoO 4 //AC (32.5 Wh kg −1 and 750 W kg −1 ), 38 CoMoO 4 /Co−B//AC (23.18 Wh kg −1 and 200.5 W kg −1 ), 72 Ni 2 B/RGO//AC (22.1 Wh kg −1 and 724.9 W kg −1 ), 28 Ni−B//AC (26.04 Wh kg −1 and 2.08 kW kg −1 ), 73 and NiCoP@CoS//AC (35.8 Wh kg −1 and 748.9 W kg −1 ). 60 The successful construction of NiCoP@NiCo−B-70//AC ASC provides inspiration for designing aqueous alkaline electrolyte devices with higher energy/power density.…”

“…70// AC ASC reaches an energy density of 40.8 Wh kg −1 at a power density of 400.0 W kg −1 , and the energy density of 21.3 Wh kg −1 can be retained even at a maximum power density of 4000.0 W kg −1 , which outperforms other reported asymmetric energy storage devices, such as Ni x B/MnMoO 4 //AC (32.5 Wh kg −1 and 750 W kg −1 ),38 CoMoO 4 /Co−B//AC (23.18 Wh kg −1 and 200.5 W kg −1 ),72 Ni 2 B/RGO//AC (22.1 Wh kg −1 and 724.9 W kg −1 ),28 Ni−B//AC (26.04 Wh kg −1 and 2.08 kW kg −1 ),…”

“…More importantly, in comparison to crystalline materials, the amorphous materials have a random network arrangement of atoms with a short-range ordering structure, which can facilitate the electrolyte ion diffusion and supply more reaction sites as a result of a large number of surface defects and the isotropic nature of amorphous materials. 32−34 Logically, the rational design of core−shell heterostructures by integrating a crystalline core with an amorphous shell, such as crystalline−amorphous core−shell heterostructures Ni 3 P@Ni x (PO y ) z , 35 NiSe 2 − Fe 3 Se 4 @NiCoB, 36 Ni 9 S 8 @Ni 2 B, 37 MnMoO 4 /Ni x B, 38 and NiMoO 4 @Co−B, 39 should be an attractive strategy for further enhancing the electrochemical performance of electrodes, because the crystalline core can provide stable mechanical support and the amorphous shell can improve the electrochemical active area. 40 Encouraged by the mentioned considerations, the crystalline/ amorphous NiCoP@NiCo−B-70 core−shell nanospheres are synthesized, where the nanosheet-assembled NiCoP hollow nanospheres and amorphous NiCo−B serve as the core and shell, respectively.…”