A Facile Strategy to Construct Silver‐Modified,ZnO‐Incorporated and Carbon‐Coated Silicon/Porous‐Carbon Nanofibers with Enhanced Lithium Storage

For Si anode materials used for lithium ion batteries (LIBs), developing an effective solution to overcome their drawbacks of large volume change and poor electronic conductivity is highly desirable. Here, the composites of ZnO‐incorporated and carbon‐coated silicon/porous‐carbon nanofibers (ZnO‐Si@C‐PCNFs) are designed and synthesized via a traditional electrospinning method. The prepared ZnO‐Si@C‐PCNFs can obviously overcome these two drawbacks and provide excellent LIB performance with excellent rate capability and stable long cycling life of 1000 cycles with reversible capacity of 1050 mA h g^?1 at 800 mA g^?1. Meanwhile, anodes of ZnO‐Si@C‐PCNFs attached with Ag particles display enhanced LIB performance, maintaining an average capacity of 920 mA h g^?1 at a large current of 1800 mA g^?1 even for 1000 cycles with negligible capacity loss and excellent reversibility. In addition, the assembling method with important practical significance for a simple pouch full cell is designed and used to evaluate the active materials. The Ag/ZnO‐Si@C‐PCNFs are prelithiated and assembled in full cells using LiNi_0.5Co_0.2Mn_0.3O₂(NCM523) as cathodes, exhibiting higher energy density (230 W h kg^?1) of 18% than that of 195 W h kg^?1 for commercial graphite//NCM523 full pouch cells. Importantly, the comprehensive mechanisms of enhanced electrochemical kinetics originating from ZnO‐incorporation and Ag‐attachment are revealed in detail.     

High‐Stacking‐Density,Superior‐Roughness LDH Bridged with Vertically Aligned Graphene for High‐Performance Asymmetric Supercapacitors

The high‐performance electrode materials with tuned surface and interface structure and functionalities are highly demanded for advanced supercapacitors. A novel strategy is presented to conFigure high‐stacking‐density, superior‐roughness nickel manganese layered double hydroxide (LDH) bridged by vertically aligned graphene (VG) with nickel foam (NF) as the conductive collector, yielding the LDH‐NF@VG hybrids for asymmetric supercapacitors. The VG nanosheets provide numerous electron transfer channels for quick redox reactions, and well‐developed open structure for fast mass transport. Moreover, the high‐stacking‐density LDH grown and assembled on VG nanosheets result in a superior hydrophilicity derived from the tuned nano/microstructures, especially microroughness. Such a high stacking density with abundant active sites and superior wettability can be easily accessed by aqueous electrolytes. Benefitting from the above features, the LDH‐NF@VG can deliver a high capacitance of 2920 F g^?1 at a current density of 2 A g^?1, and the asymmetric supercapacitor with the LDH‐NF@VG as positive electrode and activated carbon as negative electrode can deliver a high energy density of 56.8 Wh kg^?1 at a power density of 260 W kg^?1, with a high specific capacitance retention rate of 87% even after 10 000 cycles.     

Polyhedral‐Like NiMn‐Layered Double Hydroxide/Porous Carbon as Electrode for Enhanced Electrochemical Performance Supercapacitors

Polyhedral‐like NiMn‐layered double hydroxide/porous carbon (NiMn‐LDH/PC‐x ) composites are successfully synthesized by hydrothermal method (x = 1, 2 means different mass percent of porous carbon (PC) in composites). The NiMn‐LDH/PC‐1 composites possess specific capacitance 1634 F g⁻¹ at a current density of 1 A g⁻¹, and it is much better than that of pure LDH (1095 F g⁻¹ at 1 A g⁻¹). Besides, the sample can retain 84.58% of original capacitance after 3000 cycles at 15 A g⁻¹. An asymmetric supercapacitor with NiMn‐LDH/PC‐1 as anode and activated carbon as cathode is fabricated, and the supercapacitor can achieve an energy density of 18.60 Wh kg⁻¹ at a power density of 225.03 W kg⁻¹. The enhanced electrochemical performance attributes to the high faradaic pseudocapacitance of NiMn‐LDH, the introduction of PC, and the 3D porous structure of LDH/PC‐1 composites. The introduction of PC hinders serious agglomeration of LDH and further accelerates ions transport. The encouraging results indicate that these materials are one of the most potential candidates for energy storage devices.     

Boosting Zn‐Ion Energy Storage Capability of Hierarchically Porous Carbon by Promoting Chemical Adsorption

The construction of advanced Zn‐ion hybrid supercapacitors (ZHSCs) with high energy density is promising but still challenging, especially at high current densities. In this work, a high‐energy and ultrastable aqueous ZHSC is demonstrated by introducing N dopants into a hierarchically porous carbon cathode for the purpose of enhancing its chemical adsorption of Zn ions. Experimental results and theoretical simulations reveal that N doping not only significantly facilitates the chemical adsorption process of Zn ions, but also greatly increases its conductivity, surface wettability, and active sites. Consequently, the as‐fabricated aqueous ZHSC based on this N‐doped porous carbon cathode displays an exceptionally high energy density of 107.3 Wh kg^?1 at a high current density of 4.2 A g^?1, a superb power density of 24.9 kW kg^?1, and an ultralong‐term lifespan (99.7% retention after 20 000 cycles), substantially superior to state‐of‐the‐art ZHSCs. Particularly, such a cathode also leads to a quasi‐solid‐state device with satisfactory energy storage performance, delivering a remarkable energy density of 91.8 Wh kg^?1. The boosted energy storage strategy by tuning the chemical adsorption capability is also applicable to other carbon materials.     

Ultra‐High Pyridinic N‐Doped Porous Carbon Monolith Enabling High‐Capacity K‐Ion Battery Anodes for Both Half‐Cell and Full‐Cell Applications

An ultrahigh pyridinic N‐content‐doped porous carbon monolith is reported, and the content of pyridinic N reaches up to 10.1% in overall material (53.4 ± 0.9% out of 18.9 ± 0.4% N content), being higher than most of previously reported N‐doping carbonaceous materials, which exhibit greatly improved electrochemical performance for potassium storage, especially in term of the high reversible capacity. Remarkably, the pyridinic N‐doped porous carbon monolith (PNCM) electrode exhibits high initial charge capacity of 487 mAh g^?1 at a current density of 20 mA g^?1, which is one of the highest reversible capacities among all carbonaceous anodes for K‐ion batteries. Moreover, the K‐ion full cell is successfully assembled, demonstrating a high practical energy density of 153.5 Wh kg^?1. These results make PNCM promising for practical application in energy storage devices and encourage more investigations on a similar potassium storage system.     

Hollow Carbon Nanobelts Codoped with Nitrogen and Sulfur via a Self‐Templated Method for a High‐Performance Sodium‐Ion Capacitor

Sodium‐ion capacitors (SICs) have attracted enormous attention due to their high energy density and high power density. In this work, N and S codoped hollow carbon nanobelts (N/S‐HCNs) are synthesized by a self‐templated method. The as‐synthesized carbon nanobelts exhibit excellent performance in pseudocapacitance and electric double layer anions adsorption. After pairing the N/S‐HCNs cathode with a tin foil anode in a carbonate electrolyte, the obtained SIC achieves a high specific capacity of 400 mAh g^?1 at 1 A g^?1 (based on the mass of cathode material) and energy density of 250.35 Wh kg^?1 at 676 W kg^?1 (based on the total mass of cathode and anode materials). Besides, the presented SIC also demonstrates high cycling stability with almost 100% capacity retention after 10 000 cycles, which is among the best results of the reported SICs, suggesting the potential for high‐performance energy storage applications.     

Hierarchical 3D All‐Carbon Composite Structure Modified with N‐Doped Graphene Quantum Dots for High‐Performance Flexible Supercapacitors

Flexible supercapacitors have shown enormous potential for portable electronic devices. Herein, hierarchical 3D all‐carbon electrode materials are prepared by assembling N‐doped graphene quantum dots (N‐GQDs) on carbonized MOF materials (cZIF‐8) interweaved with carbon nanotubes (CNTs) for flexible all‐solid‐state supercapacitors. In this ternary electrode, cZIF‐8 provides a large accessible surface area, CNTs act as the electrical conductive network, and N‐GQDs serve as highly pseudocapactive materials. Due to the synergistic effect and hierarchical assembly of these components, N‐GQD@cZIF‐8/CNT electrodes exhibit a high specific capacitance of 540 F g^?1 at 0.5 A g^?1 in a 1 m H₂SO₄ electrolyte and excellent cycle stability with 90.9% capacity retention over 8000 cycles. The assembled supercapacitor possesses an energy density of 18.75 Wh kg^?1 with a power density of 108.7 W kg^?1. Meanwhile, three supercapacitors connected in series can power light‐emitting diodes for 20 min. All‐solid‐state N‐GQD@cZIF‐8/CNT flexible supercapacitor exhibits an energy density of 14 Wh kg^?1 with a power density of 89.3 W kg^?1, while the capacitance retention after 5000 cycles reaches 82%. This work provides an effective way to construct novel electrode materials with high energy storage density as well as good cycling performance and power density for high‐performance energy storage devices via the rational design.     

Biomass‐Derived Nitrogen‐Doped Carbon Nanofiber Network: A Facile Template for Decoration of Ultrathin Nickel‐Cobalt Layered Double Hydroxide Nanosheets as High‐Performance Asymmetric Supercapacitor Electrode

The development of biomass‐based energy storage devices is an emerging trend to reduce the ever‐increasing consumption of non‐renewable resources. Here, nitrogen‐doped carbonized bacterial cellulose (CBC‐N) nanofibers are obtained by one‐step carbonization of polyaniline coated bacterial cellulose (BC) nanofibers, which not only display excellent capacitive performance as the supercapacitor electrode, but also act as 3D bio‐template for further deposition of ultrathin nickel‐cobalt layered double hydroxide (Ni‐Co LDH) nanosheets. The as‐obtained CBC‐N@LDH composite electrodes exhibit significantly enhanced specific capacitance (1949.5 F g^?1 at a discharge current density of 1 A g^?1, based on active materials), high capacitance retention of 54.7% even at a high discharge current density of 10 A g^?1 and excellent cycling stability of 74.4% retention after 5000 cycles. Furthermore, asymmetric supercapacitors (ASCs) are constructed using CBC‐N@LDH composites as positive electrode materials and CBC‐N nanofibers as negative electrode materials. By virtue of the intrinsic pseudocapacitive characteristics of CBC‐N@LDH composites and 3D nitrogen‐doped carbon nanofiber networks, the developed ASC exhibits high energy density of 36.3 Wh kg^?1 at the power density of 800.2 W kg^?1. Therefore, this work presents a novel protocol for the large‐scale production of biomass‐derived high‐performance electrode materials in practical supercapacitor applications.     

Hierarchical porous carbon obtained from directly carbonizing carex meyeriana for high-performance supercapacitors

Hierarchical porous carbon materials with high surface area are facilely prepared by directly carbonizing carex meyeriana without any extra activation procedure. The as-prepared porous carbon samples possess high Brunauer–Emmett–Teller (BET) surface areas (in the?~?518–742 m² g^?1 range) and unique hierarchical porous structure containing macropore channels and mesopores and micropores developed in the wall of macropores. These intriguing characteristics make the as-prepared hierarchical porous carbon samples a promising electrode material for supercapacitors. The capacitive performance was measured in the three-electrode system with 6 M KOH electrolyte. The hierarchical porous carbon prepared at the carbonization temperature of 1000 °C presents a high specific capacitance of 178.6 F g^?1 at a current density of 0.5 A g^?1, a good rate performance ( about 65.2% retention ratio at the current density of 20 A g^?1), and an excellent cycling stability (no obvious performance fading after 10,000 cycles). In addition, the fabricated two-electrode device achieves an energy density of 4.33 Wh kg^?1 at a high power density of 5 kW kg^?1. These results provide a green and facile method to synthesize the electrode material from biomass for high-performance supercapacitors.

     

Etching‐Assisted Crumpled Graphene Wrapped Spiky Iron Oxide Particles for High‐Performance Li‐Ion Hybrid Supercapacitor

From graphene oxide wrapped iron oxide particles with etching/reduction process, high‐performance anode and cathode materials of lithium‐ion hybrid supercapacitors are obtained in the same process with different etching conditions, which consist of partially etched crumpled graphene (CG) wrapped spiky iron oxide particles (CG@SF) for a battery‐type anode, and fully etched CG for a capacitive‐type cathode. The CG is formed along the shape of spikily etched particles, resulting in high specific surface area and electrical conductivity, thus the CG‐based cathode exhibits remarkable capacitive performance of 210 F g^?1 and excellent rate capabilities. The CG@SF can also be ideal anode materials owing to spiky and porous morphology of the particles and tightly attached crumpled graphene onto the spiky particles, which provides structural stability and low contact resistance during repetitive lithiation/delithiation processes. The CG@SF anode shows a particularly high capacitive performance of 1420 mAh g^?1 after 270 cycles, continuously increases capacity beyond the 270th cycle, and also maintains a high capacity of 170 mAh g^?1 at extremely high speeds of 100 C. The full‐cell exhibits a higher energy density up to 121 Wh kg^?1 and maintains high energy density of 60.1 Wh kg^?1 at 18.0 kW kg^?1. This system could thus be a practical energy storage system to fill the gap between batteries and supercapacitors.     

N‐Doped Carbon Nanofibers with Interweaved Nanochannels for High‐Performance Sodium‐Ion Storage

Although graphite materials have been applied as commercial anodes in lithium‐ion batteries (LIBs), there still remain abundant spaces in the development of carbon‐based anode materials for sodium‐ion batteries (SIBs). Herein, an electrospinning route is reported to fabricate nitrogen‐doped carbon nanofibers with interweaved nanochannels (NCNFs‐IWNC) that contain robust interconnected 1D porous channels, produced by removal of a Te nanowire template that is coelectrospun within carbon nanofibers during the electrospinning process. The NCNFs‐IWNC features favorable properties, including a conductive 1D interconnected porous structure, a large specific surface area, expanded interlayer graphite‐like spacing, enriched N‐doped defects and active sites, toward rapid access and transport of electrolyte and electron/sodium ions. Systematic electrochemical studies indicate that the NCNFs‐IWNC exhibits an impressively high rate capability, delivering a capacity of 148 mA h g^?1 at current density of as high as 10 A g^?1, and has an attractively stable performance over 5000 cycles. The practical application of the as‐designed NCNFs‐IWNC for a full SIBs cell is further verified by coupling the NCNFs‐IWNC anode with a FeFe(CN)₆ cathode, which displays a desirable cycle performance, maintaining acapacity of 97 mA h g^?1 over 100 cycles.     

Mineral‐Templated 3D Graphene Architectures for Energy‐Efficient Electrodes

3D graphene networks have shown extraordinary promise for high‐performance electrochemical devices. Herein, the chemical vapor deposition synthesis of a highly porous 3D graphene foam (3D‐GF) using naturally abundant calcined Iceland crystal as the template is reported. Intriguingly, the Iceland crystal transforms to CaO monolith with evenly distributed micro/meso/macropores through the releasing of CO₂ at high temperature. Meanwhile, the hierarchical structure of the calcined template could be easily tuned under different calcination conditions. By precisely inheriting fine structure from the templates, the as‐prepared 3D‐GF possesses a tunable hierarchical porosity and low density. Thus, the hierarchical pores offer space for guest hybridization and provide an efficient pathway for ion/charge transport in typical energy conversion/storage systems. The 3D‐GF skeleton electrode hybridized with Ni(OH)₂/Co(OH)₂ through an optimal electrodeposition condition exhibits a high specific capacitance of 2922.2 F g⁻¹ at a scan rate of 10 mV s⁻¹, and 2138.4 F g⁻¹ at a discharge current density of 3.1 A g⁻¹. The hybrid 3D‐GF symmetry supercapacitor shows a high energy density of 83.0 Wh kg⁻¹ at a power density of 1011.3 W kg⁻¹ and 31.4 Wh kg⁻¹ at a high power density of 18 845.2 W kg⁻¹. The facile fabrication process enables the mass production of hierarchical porous 3D‐GF for high‐performance supercapacitors.     

Controlled Air‐Etching Synthesis of Porous‐Carbon Nanotube Aerogels with Ultrafast Charging at 1000 A g−1

Supercapacitors are energy storage systems capable of fast charging and discharging, thus generating superior power density. Porous carbon with high surface area and tunable pore size represents a promising candidate to construct ultrafast supercapacitors; so far, most porous carbon–based electrodes can only be charged to a moderate current density (100–200 A g^?1), also with significant capacitance loss at increasing rate. Here, it is shown that a 3D aerogel consisting of interconnected 1D porous‐carbon nanotubes (PCNs) can serve as a freestanding supercapacitor electrode with excellent rate performance. As a result, the PCN aerogel electrodes achieve 1) ultrafast charging at current densities up to 1000 A g^?1 (corresponding to a charge period of 16 ms), which is the highest value among other porous carbon–based supercapacitors, 2) superior cycling stability at high charging rates (88% capacitance retention after 10⁵ cycles at 1000 A g^?1). Mechanism study reveals favorable kinetics including a centralized pore size distribution at 0.8 nm which is a dominant factor to allow high‐rate charging, a low and linear IR drop, and a metallic feature of 1D PCNs by theoretical calculation. The results indicate that 1D PCNs with controlled porous structures have potential applications in ultrafast energy conversion and storage.     

A Nonaqueous Potassium‐Based Battery–Supercapacitor Hybrid Device

A low cost nonaqueous potassium‐based battery–supercapacitor hybrid device (BSH) is successfully established for the first time with soft carbon as the anode, commercialized activated carbon as the cathode, and potassium bis(fluoro‐slufonyl)imide in dimethyl ether as the electrolyte. This BSH reconciles the advantages of potassium ion batteries and supercapacitors, achieving a high energy density of 120 W h kg^?1, a high power density of 599 W kg^?1, a long cycle life of 1500 cycles, and an ultrafast charge/slow discharge performance (energy density and power density are calculated based on the total mass of active materials in the anode and cathode). This work demonstrates a great potential of applying the nonaqueous BSH for low cost electric energy storage systems.     

Birnessite Nanosheet Arrays with High K Content as a High‐Capacity and Ultrastable Cathode for K‐Ion Batteries

Potassium‐ion batteries (PIBs) are one of the emerging energy‐storage technologies due to the low cost of potassium and theoretically high energy density. However, the development of PIBs is hindered by the poor K⁺ transport kinetics and the structural instability of the cathode materials during K⁺ intercalation/deintercalation. In this work, birnessite nanosheet arrays with high K content (K_0.77MnO₂?0.23H₂O) are prepared by “hydrothermal potassiation” as a potential cathode for PIBs, demonstrating ultrahigh reversible specific capacity of about 134 mAh g^?1 at a current density of 100 mA g^?1, as well as great rate capability (77 mAh g^?1 at 1000 mA g^?1) and superior cycling stability (80.5% capacity retention after 1000 cycles at 1000 mA g^?1). With the introduction of adequate K⁺ ions in the interlayer, the K‐birnessite exhibits highly stabilized layered structure with highly reversible structure variation upon K⁺ intercalation/deintercalation. The practical feasibility of the K‐birnessite cathode in PIBs is further demonstrated by constructing full cells with a hard–soft composite carbon anode. This study highlights effective K⁺‐intercalation for birnessite to achieve superior K‐storage performance for PIBs, making it a general strategy for developing high‐performance cathodes in rechargeable batteries beyond lithium‐ion batteries.     

Covalent‐Organic‐Framework‐Based Li–CO2 Batteries

Covalent organic frameworks (COFs) are an emerging class of porous crystalline materials constructed from designer molecular building blocks that are linked and extended periodically via covalent bonds. Their high stability, open channels, and ease of functionalization suggest that they can function as a useful cathode material in reversible lithium batteries. Here, a COF constructed from hydrazone/hydrazide‐containing molecular units, which shows good CO₂ sequestration properties, is reported. The COF is hybridized to Ru‐nanoparticle‐coated carbon nanotubes, and the composite is found to function as highly efficient cathode in a Li–CO₂ battery. The robust 1D channels in the COF serve as CO₂^– and lithium‐ion‐diffusion channels and improve the kinetics of electrochemical reactions. The COF‐based Li–CO₂ battery exhibits an ultrahigh capacity of 27 348 mAh g^?1 at a current density of 200 mA g^?1, and a low cut‐off overpotential of 1.24 V within a limiting capacity of 1000 mAh g^?1. The rate performance of the battery is improved considerably with the use of the COF at the cathode, where the battery shows a slow decay of discharge voltage from a current density of 0.1 to 4 A g^?1. The COF‐based battery runs for 200 cycles when discharged/charged at a high current density of 1 A g^?1.     

Peapod‐like Li3VO4/N‐Doped Carbon Nanowires with Pseudocapacitive Properties as Advanced Materials for High‐Energy Lithium‐Ion Capacitors

Lithium ion capacitors are new energy storage devices combining the complementary features of both electric double‐layer capacitors and lithium ion batteries. A key limitation to this technology is the kinetic imbalance between the Faradaic insertion electrode and capacitive electrode. Here, we demonstrate that the Li₃VO₄ with low Li‐ion insertion voltage and fast kinetics can be favorably used for lithium ion capacitors. N‐doped carbon‐encapsulated Li₃VO₄ nanowires are synthesized through a morphology‐inheritance route, displaying a low insertion voltage between 0.2 and 1.0 V, a high reversible capacity of ≈400 mAh g^?1 at 0.1 A g^?1, excellent rate capability, and long‐term cycling stability. Benefiting from the small nanoparticles, low energy diffusion barrier and highly localized charge‐transfer, the Li₃VO₄/N‐doped carbon nanowires exhibit a high‐rate pseudocapacitive behavior. A lithium ion capacitor device based on these Li₃VO₄/N‐doped carbon nanowires delivers a high energy density of 136.4 Wh kg^?1 at a power density of 532 W kg^?1, revealing the potential for application in high‐performance and long life energy storage devices.     

Rational Construction of Hollow Core‐Branch CoSe2 Nanoarrays for High‐Performance Asymmetric Supercapacitor and Efficient Oxygen Evolution

Metal selenides have great potential for electrochemical energy storage, but are relatively scarce investigated. Herein, a novel hollow core‐branch CoSe₂ nanoarray on carbon cloth is designed by a facile selenization reaction of predesigned CoO nanocones. And the electrochemical reaction mechanism of CoSe₂ in supercapacitor is studied in detail for the first time. Compared with CoO, the hollow core‐branch CoSe₂ has both larger specific surface area and higher electrical conductivity. When tested as a supercapacitor positive electrode, the CoSe₂ delivers a high specific capacitance of 759.5 F g^?1 at 1 mA cm^?2, which is much larger than that of CoO nanocones (319.5 F g^?1). In addition, the CoSe₂ electrode exhibits excellent cycling stability in that a capacitance retention of 94.5% can be maintained after 5000 charge–discharge cycles at 5 mA cm^?2. An asymmetric supercapacitor using the CoSe₂ as cathode and an N‐doped carbon nanowall as anode is further assembled, which show a high energy density of 32.2 Wh kg^?1 at a power density of 1914.7 W kg^?1, and maintains 24.9 Wh kg^?1 when power density increased to 7354.8 W kg^?1. Moreover, the CoSe₂ electrode also exhibits better oxygen evolution reaction activity than that of CoO.     

Confined Amorphous Red Phosphorus in MOF‐Derived N‐Doped Microporous Carbon as a Superior Anode for Sodium‐Ion Battery

Red phosphorus (P) has attracted intense attention as promising anode material for high‐energy density sodium‐ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g^?1). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework‐8 (ZIF‐8) ‐derived nitrogen‐doped microporous carbon matrix (denoted as P@N‐MPC). When used as anode for NIBs, the P@N‐MPC composite displays a high reversible specific capacity of ≈600 mAh g^?1 at 0.15 A g^?1 and improved rate capacity (≈450 mAh g^?1 at 1 A g^?1 after 1000 cycles with an extremely low capacity fading rate of 0.02% per cycle). The superior sodium storage performance of the P@N‐MPC is mainly attributed to the novel structure. The N‐doped porous carbon with sub‐1 nm micropore facilitates the rapid diffusion of organic electrolyte ions and improves the conductivity of the encapsulated red P. Furthermore, the porous carbon matrix can buffer the volume change of red P during repeat sodiation/desodiation process, keeping the structure intact after long cycle life.     

MoS2/NiS Yolk–Shell Microsphere‐Based Electrodes for Overall Water Splitting and Asymmetric Supercapacitor

Rational designing of the composition and structure of electrode material is of great significance for achieving highly efficient energy storage and conversion in electrochemical energy devices. Herein, MoS₂/NiS yolk–shell microspheres are successfully synthesized via a facile ionic liquid‐assisted one‐step hydrothermal method. With the favorable interface effect and hollow structure, the electrodes assembled with MoS₂/NiS hybrid microspheres present remarkably enhanced electrochemical performance for both overall water splitting and asymmetric supercapacitors. In particular, to deliver a current density of 10 mA cm^?2, the MoS₂/NiS‐based electrolysis cell for overall water splitting only needs an output voltage of 1.64 V in the alkaline medium, lower than that of Pt/C–IrO₂‐based electrolysis cells (1.70 V). As an electrode for supercapacitors, the MoS₂/NiS hybrid microspheres exhibit a specific capacitance of 1493 F g^?1 at current density of 0.2 A g^?1, and remain 1165 F g^?1 even at a large current density of 2 A g^?1, implying outstanding charge storage capacity and excellent rate performance. The MoS₂/NiS‐ and active carbon‐based asymmetric supercapacitor manifests a maximum energy density of 31 Wh kg^?1 at a power density of 155.7 W kg^?1, and remarkable cycling stability with a capacitance retention of approximately 100% after 10 000 cycles.