Cycling Capacity Retention Research Articles

Synergy of Artificial SEI and Electrolyte Additive for Improved Performance of Silicon Electrodes in Li-Ion Batteries.

Maintaining the electrochemically and mechanically stable solid electrolyte interphase (SEI) is of highest importance for the performance of high-capacity anode materials such as silicon (Si). Applying flexible Li-ion permeable coatings to the electrode surface using molecular layer deposition (MLD) offers a strategy to improve the properties of the SEI and greatly contributes to an increase in the cycle life and capacity retention of Si electrodes. In this study, the long-term cycling of Si electrodes with an MLD alucone coating is investigated in the context of more stable SEI formation. When the joined strategy introducing both MLD coating and anFEC electrolyte additive was realized, high performance of Si anodes was achieved, capable of delivering more than 1500 mAh g-1 even after 400 cycles. The reason for the significantly improved longevity is the ability of the alucone layer to react with HF present in LiPF6-based electrolytes already under OCV-like conditions, fluorinating most of the available -OH groups in the alucone structure. This reaction not only partially scavenges hydrofluoric acid but also does not disturb the confining effect of alucone-like fluorinated artificial SEI. This study shows the significance of searching for synergetic solutions, such as a combination of electrode surface modification and electrolyte composition, for maximizing the capacity retention of Si as an active material or as a capacity-enhancing additive to graphite electrodes, and as well can be applied to other high-energy battery materials with large volume changes during cycling.

Sulfur Distribution Analysis in Lithium−Sulfur Cathode via Confined Inverse Vulcanization in Carbon Frameworks

AbstractLithium–Sulfur (Li–S) batteries are promising energy storage devices due to their high theoretical energy density. However, challenges such as the shuttling effect and volume expansion have significantly hindered their cycle life and capacity retention. Furthermore, the complex kinetic pathways in Li–S batteries call for advanced characterization techniques to unravel underlying mechanisms. In this study, a hollow porous carbon (HPC) is used as a microreactor, where inverse vulcanization occurs between 1,3‐diisopropylbenzene (DIB) and sulfur (S8), resulting in the creation of three‐dimensionally interconnected and well‐distributed S‐DIB in carbon frameworks. As a result, the dual confinement strategy imparts Li–S coin cells with remarkable cycling stability and capacity retention, exhibiting an impressive capacity of 866 mAh g−1 when returning to 0.1 C after 100 cycles of rate capability tests. Particularly, the Energy‐selective Backscattered (EsB) assisted Scanning Electron Microscope (SEM) technique as a novel approach is introduced to distinguish different lengths of polysulfides. Their distribution is visualized in the cross‐section view of the electrode in a micrometer range. These EsB images provide concrete indications of the sulfur evolution process and explain the capacity degradation during cycling.

An Effective Strategy on Synthesizing a Stable SiOx-Based Anode for High Density Lithium-Ion Batteries.

Silicon oxides (SiOx) have received extensive attention as a promising anode candidate for next-generation lithium-ion batteries (LIBs). However, their commercial applications have been seriously hindered by low conductivity, large volume expansion, and unstable solid-electrolyte interface (SEI) layer, which result in low initial coulombic efficiency, poor rate performance, and short cycling lifespan. In this work, we demonstrated a simple way to prepare a series of SiOx materials with lithium fluoride (LiF) modified. When the mass ratio of SiOx and LiF equaled 1 : 0.15, the long-term cycling capacity retention could be greatly improved from 30.1 % to 76.5 % after 300 cycles. The result was primarily because of the enhancement of electrons and Li+-ions transport and the stability of the SEI layer due to LiF addition. However, excess LiF addition could hinder the diffusion of Li+-ions. This study presented the great potential of LiF modified on SiOx anode materials for LIBs.

Graphene oxide modified with magnesium hydroxide derived from dolomites for dyes adsorptions and supercapacitor

This research highlights the novelty of using dolomite as an Mg(OH)2 source for synthesizing GO/Mg(OH)2 nanocomposite, a dye adsorbent and supercapacitor material. So far, dolomite has only been conventionally used as fertilizer and building material. By utilizing dolomite as Mg(OH)2 raw materials, this nanocomposite shows high efficiency in removing methylene blue (MB) up to 97 % with adsorption kinetics following a pseudo-second-order model. At an optimal pH of 5, this material can be used repeatedly with satisfactory results. For supercapacitor applications, GO/Mg(OH)2 has a specific capacitance of 117.80 F g−1 at a current density of 0.5 A g−1 and 90 % cyclic capacity retention, making it an excellent candidate in modern energy storage technology.

Simultaneous structure and surface engineering of metal-organic framework derived LiNi0.5-xFe2xMn1.5-xO4 cathode material for improving high voltage performance of lithium-ion batteries

This study presents a novel material synthesis approach utilizing a terephthalic acid-based metal-organic framework as a precursor and employing an ethanol-assisted hydrothermal treatment to produce high-performance Fe-doped LiNi0.5Mn1.5O4 (LNMO) cathode material. This strategy yields a well-crystallized spinel structure with uniformly distributed transition metal ions. Additionally, the appropriate quantity of Fe dopant can achieve the desired Mn3+/Mn4+ ratio, level of structural disordering, and crystal phase purity for Fe-doped LNMO. The synthesis process also aids in forming an amorphous Li2CO3 surface layer, approximately 1 nm thick, which protects the active material from excessive reaction with electrolyte. The typical Fe-doped LNMO cathode (S-05) exhibits superior performance compared to a commercialized LNMO counterpart. It delivers an initial discharge capacity of 135 mAh g-1 at 1 C with exceptional cycling stability over 500 cycles (capacity retention of 90%) under high voltage (5.0 V vs. Li+/Li). Furthermore, its rate capability significantly improves, with a capacity retention of 85% (5 C/0.2 C). This enhanced performance aligns with evidence of activated Ni2+/Ni3+/Ni4+ redox reactions and suppressed cathode electrolyte interphase resistance, leading to promoted Li+ diffusion. Moreover, it is found the cathode helps alleviate electrolyte degradation at high voltages by inhibiting the formation of singlet oxygen in the electrolyte.

High‐Performance Polyimide Covalent Organic Frameworks for Lithium‐Ion Batteries: Exceptional Stability and Capacity Retention at High Current Densities

Organic polymers are considered promising candidates for next‐generation green electrode materials in lithium‐ion batteries (LIBs). However, achieving long cycling stability and capacity retention at high current densities remains a significant challenge due to weak structural stability and low conductivity. In this study, we report the synthesis of two novel polyimide covalent organic frameworks (PI‐COFs), COF‐JLU85 and COF‐JLU86, by combining truxenone‐based triamine and linear acid anhydride through polymerization. These PI‐COFs feature layers with pore channels embedded with 18 carbonyl groups, facilitating rapid lithium‐ion diffusion and enhancing structural stability under high current densities. Compared to previously reported organic polymer materials, COF‐JLU86 demonstrates the excellent performance at high current densities, with an impressive specific capacity of 1161.1 mA h g‐1 at 0.1 A g‐1, and outstanding cycling stability, retaining 1289.8 mA h g at 2 A g‐1 after 1500 cycles and 401.1 mA h g‐1 at 15 A g‐1 after 10000 cycles. Additionally, in‐situ infrared spectroscopy and density functional theory (DFT) calculations provide mechanistic insights, revealing that the high concentration of carbonyl redox‐active sites and the optimized electronic structure contribute to the excellent electrochemical performance.

High-Performance Polyimide Covalent Organic Frameworks for Lithium-Ion Batteries: Exceptional Stability and Capacity Retention at High Current Densities.

Organic polymers are considered promising candidates for next-generation green electrode materials in lithium-ion batteries (LIBs). However, achieving long cycling stability and capacity retention at high current densities remains a significant challenge due to weak structural stability and low conductivity. In this study, we report the synthesis of two novel polyimide covalent organic frameworks (PI-COFs), COF-JLU85 and COF-JLU86, by combining truxenone-based triamine and linear acid anhydride through polymerization. These PI-COFs feature layers with pore channels embedded with 18 carbonyl groups, facilitating rapid lithium-ion diffusion and enhancing structural stability under high current densities. Compared to previously reported organic polymer materials, COF-JLU86 demonstrates the excellent performance at high current densities, with an impressive specific capacity of 1161.1 mA h g-1 at 0.1 A g-1, and outstanding cycling stability, retaining 1289.8 mA h g at 2 A g-1 after 1500 cycles and 401.1 mA h g-1 at 15 A g-1 after 10000 cycles. Additionally, in-situ infrared spectroscopy and density functional theory (DFT) calculations provide mechanistic insights, revealing that the high concentration of carbonyl redox-active sites and the optimized electronic structure contribute to the excellent electrochemical performance.

Scalable Ni12P5-Coated Carbon Cloth Cathode for Lithium–Sulfur Batteries

As a better alternative to lithium-ion batteries (LIBs), lithium–sulfur batteries (LSBs) stand out because of their multi-electron redox reactions and high theoretical specific capacity (1675 mA h g−1). However, the long-term stability of LSBs and their commercialization are significantly compromised by the inherently irreversible transition of soluble lithium polysulfides (LiPS) into solid short-chain S species (Li2S2 and Li2S) and the resulting substantial density change in S. To address these issues, we used activated carbon cloth (ACC) coated with Ni12P5 as a porous, conductive, and scalable sulfur host material for LSBs. ACC has the benefit of high electrical conductivity, high surface area, and a three-dimensional (3D) porous architecture, allowing for ion transport channels and void spaces for the volume expansion of S upon lithiation. Ni12P5 accelerates the breakdown of Li2S to increase the efficiency of active materials and trap soluble polysulfides. The highly effective Ni12P5 electrocatalyst supported on ACC drastically reduced the severity of the LiPS shuttle, affected the abundance of adsorption–diffusion–conversion interfaces, and demonstrated outstanding performance. Our cells achieved near theoretical capacity (>1611 mA h g−1) during initial cycling and superior capacity retention (87%) for >250 cycles following stabilization with a 0.05% decay rate per cycle at 0.2 C.

Zein protein-functionalized separator through a viable method for trapping polysulfides and regulating ion transport in Li[sbnd]S batteries

Commercialization of lithium‑sulfur (LiS) batteries as a promising energy storage system, is primarily impeded by polysulfide shuttling and uncontrollable lithium dendrite growth. To address the issues for improving the performance of LiS batteries, we decorate the separator with zein (corn protein) via a simple soaking process. Owing to strong zein–polysulfide interactions, the zein-soaked separator effectively enhances the polysulfide-trapping capability. Moreover, abundant functional groups of zein also stabilize Li-ion deposition, and thus suppresses the growth of Li dendrites. As a result, the resulting LiS batteries exhibited enhanced electrochemical performance in terms of cycling stability, capacity retention, and rate capability. The soaking method used for coating zein on pristine separator offers a scalable solution for generating multifunctional separators toward commercialization.

Synergistic effect of in-situ carbon-coated mixed phase iron oxides and 3d electrode architectures as anodes for high-performance sodium-ion batteries

Due to the high theoretical capacity, iron-oxide-based Fe2O3 (1007 mAh g−1) and Fe3O4 (926 mAh g−1) materials can be a promising conversion-type anode material for Sodium-ion batteries (SIBs). However, the low electronic conductivity (10−14 S cm−1) and 200% volume expansion of iron oxide lead to poor cycle life and capacity retention, limiting its commercial application. In this work, carbon-coated mixed-phase iron oxide C-Fe2O3-Fe3O4 (C-IO) was synthesized by pyrolysis using ferrocene precursor. Subsequently, a 3D carbon fiber (CF) network was introduced to improve the electrochemical performance of the material by resolving the volume expansion and pulverization issues. Both the CF network and Fe3O4 provide an electron transport pathway. The conventional Cu-C-IO electrodes deliver a 2nd cycle capacity of 335 mAh g−1 at 250 mA g−1 and exhibit 61.5% capacity retention after 500 cycles. In contrast, the 3D-CF-based IO electrodes show 2nd cycle capacity of 607 mAh g−1 at 50 mA g−1 with 96.4% capacity retention after 35 cycles and 420 mAh g−1 with ∼85.4% capacity retention after 500 cycles at 250 mA g−1 (w.r.t. CF and C-IO active mass, CF contribute ∼ 27% and C-IO ∼ 73% capacity), making it a potential anode for SIBs.

All-Solid-State Lithium-Sulfur Batteries of High Cycling Stability and Rate Capability Enabled by a Self-Lithiated Sn-C Interlayer.

All-solid-state lithium-sulfur batteries (ASSLSBs) have attracted intense interest due to their high theoretical energy density and intrinsic safety. However, constructing durable lithium (Li) metal anodes with high cycling efficiency in ASSLSBs remains challenging due to poor interface stability. Here, a compositionally stable, self-lithiated tin (Sn)-carbon (C) composite interlayer (LSCI) between Li anode and solid-state electrolyte (SSE), capable of homogenizing Li-ion transport across the interlayer, mitigating decomposition of SSE, and enhancing electrochemical/structural stability of interface, is developed for ASSLSBs. The LSCI-mediated Li metal anode enables stable Li plating/stripping over 7000h without Li dendrite penetration. The ASSLSBs equipped with LSCI thus exhibit excellent cycling stability of over 300 cycles (capacity retention of ≈80%) under low applied pressure (<8MPa) and demonstrate improved rate capability even at 3C. The enhanced electrochemical performance and corresponding insights of the designed LSCI broaden the spectrum of advanced interlayers for interface manipulation, advancing the practical application of ASSLSBs.

Air-Stable High-Entropy Layered Oxide Cathode with Enhanced Cycling Stability for Sodium-Ion Batteries.

O3-type layered oxides have been extensively studied as cathode materials for sodium-ion batteries due to their high reversible capacity and high initial sodium content, but they suffer from complex phase transitions and an unstable structure during sodium intercalation/deintercalation. Herein, we synthesize a high-entropy O3-type layered transition metal oxide, NaNi0.3Cu0.05Fe0.1Mn0.3Mg0.05Ti0.2O2 (NCFMMT), by simultaneously doping Cu, Mg, and Ti into its transition metal layers, which greatly increase structural entropy, thereby reducing formation energy and enhancing structural stability. The high-entropy NCFMMT cathode exhibits significantly improved cycling stability (capacity retention of 81.4% at 1C after 250 cycles and 86.8% at 5C after 500 cycles) compared to pristine NaNi0.3Fe0.4Mn0.3O2 (71% after 100 cycles at 1C), as well as remarkable air stability. Finally, the NCFMMT//hard carbon full-cell batteries deliver a high initial capacity of 103 mAh g-1 at 1C, with 83.8 mAh g-1 maintained after 300 cycles (capacity retention of 81.4%).

Advancing Lithium-Ion Batteries' Electrochemical Performance: Ultrathin Alumina Coating on Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials.

Ni-rich Li(NixCoyMnz)O2 (x ≥ 0.8)-layered oxide materials are highly promising as cathode materials for high-energy-density lithium-ion batteries in electric and hybrid vehicles. However, their tendency to undergo side reactions with electrolytes and their structural instability during cyclic lithiation/delithiation impairs their electrochemical cycling performance, posing challenges for large-scale applications. This paper explores the application of an Al2O3 coating using an atomic layer deposition (ALD) system on Ni-enriched Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) cathode material. Characterization techniques, including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, were used to assess the impact of alumina coating on the morphology and crystal structure of NCM811. The results confirmed that an ultrathin Al2O3 coating was achieved without altering the microstructure and lattice structure of NCM811. The alumina-coated NCM811 exhibited improved cycling stability and capacity retention in the voltage range of 2.8-4.5 V at a 1 C rate. Specifically, the capacity retention of the modified NCM811 was 5%, 9.11%, and 11.28% higher than the pristine material at operating voltages of 4.3, 4.4, and 4.5 V, respectively. This enhanced performance is attributed to reduced electrode-electrolyte interaction, leading to fewer side reactions and improved structural stability. Thus, NCM811@Al2O3 with this coating process emerges as a highly attractive candidate for high-capacity lithium-ion battery cathode materials.

Li-metal free “in aqua” lithiation and re-lithiation of protected graphite anode for 4-V class aqueous lithium-ion capacitor

Lithium-ion capacitors, typically composed of a capacitive cathode and a pre-lithiated graphite anode in non-aqueous electrolyte, are promising power sources for energy harvesting applications with higher energy densities than standard electrochemical double layer capacitors. Superior energy density can be achieved by using pseudocapacitive cathodes in an aqueous electrolyte coupled with a water-stable protected anode. Lithiation of the graphite anode is one of the performance-governing processes influencing the working voltage, energy density, and cyclability of such power sources. Here, we report an effective, time-efficient, and safe lithiation procedure without the need of lithium metal or lithium-containing compounds as electrodes. The “in aqua” electrochemical lithiation of graphite is performed by using an over-sized activated carbon cathode and the salt dissolved in the aqueous electrolyte as the source of lithium ions. Subsequently, the protected anode (LixC6 + Li) is used as the counter electrode in an aqueous hybrid supercapacitor showing ∼70 % of capacity retention after 10,000 cycles. Nonetheless, the cycle life and capacity retention of the protected anode was further extended via an “in aqua” re-lithiation process allowing a 95 % retention of the initial capacity after 10,000 galvanostatic charge/discharge cycles.

Metalized Plastic Current Collectors Incorporated with Halloysite Nanotubes toward Highly Safe Lithium‐Ion Batteries

AbstractMetalized plastic current collectors (MPCCs) have shown potential in improving the energy density and safety of lithium‐ion batteries (LIBs). However, the poor mechanical strength, weak interfacial adhesion force, and surface metal corrosion have impeded the practical application of MPCCs. Here, an innovative engineering of MPCCs is proposed by incorporating halloysite nanotubes (HNTs) as fillers into polyimide (PI) polymer layer, which is further coated with two thin copper (Cu) layers. Because of the strong bonding between HNTs surface and the PI precursor, HNTs improve the mechanical strength of PI‐HNTs composite film, reinforce the interfacial adhesion force between the PI‐HNTs film and the coated Cu layer, and suppress the Cu corrosion by electrolyte. The prepared MPCCs exhibit a low mass density and only account about one‐fifth of the density of commercial Cu CCs. Furthermore, the PI‐HNTs‐Cu composite demonstrates significantly enhanced interfacial adhesion force doubled to 4 N cm−1 along with prolonged stability under electrolyte immersion and electrochemical reaction conditions, and delivers a high fracture strength of 125 MPa. LIBs assembled with MPCCs deliver a twice higher discharge capacity compared to battery with Cu CCs and reach a long‐term cycle capacity retention as high as 92.9% at 0.5 C after 500 cycles.

Sequentially epitaxial multi-shelled Mn-based Prussian blue cathode for highly stable sodium-ions batteries

The sodium manganese hexacyanoferrate (MnPB) has drawn widely attention as a remarkable cathode material for sodium-ions batteries owing to its high theoretical capacity (∼170 mAh g–1), environmental-friendly and low cost. However, it suffers from serious capacity fading and inferior cycling stability caused by the inevitable Jahn-Teller distortion and significant volume change during Na+insertion/extraction process. Herein, we propose a simple one-pot method for constructing a multi-shelled Mn-based Prussian blue through sequentially epitaxial growth CoPB and NiPB on the surface of MnPB (NiCoMnPB). The density functional theory calculations demonstrate the unequal affinities of different metal ions with various chelating agents (citrate and ferrocyanide), leading to the dissociation and recombination of metal ions and chelating agents in a certain order. Effectively inheriting merits of CoPB and NiPB, the NiCoMnPB reveals enhanced charge transfer kinetics, suppressed volume change and alleviative Jahn-Teller distortion during cycling, thereby exhibiting superior rate capacity (∼54.2 mAh g–1 at 3200 mA/g), long-term cyclic stability and capacity retention (∼76 % over 1000 cycles at 800 mA/g). This work provides a simple method to construct multi-shelled PBAs, which can integrate the virtues of different materials to ameliorate the electrochemical properties of initial materials.

Anion-doped Na2.9Fe1.7(SO4)2.7(PO4)0.3 cathode with improved cyclability and air stability for low-cost sodium-ion batteries

Polyanion-type Fe-based sulfates are one of the most promising cathode candidates for sodium-ion batteries (SIBs) due to the low cost and high voltage. However, their practical application is still hindered by the poor air stability. Herein, we report a novel anion-doped Na2.9Fe1.7(SO4)2.7(PO4)0.3 cathode material with higher air stability and faster ion/electron transport kinetics compared to pristine Na2.6Fe1.7(SO4)3 cathode as evidenced by first-principles calculations. The obtained Na2.9Fe1.7(SO4)2.7(PO4)0.3 not only manifests a high discharge capacity of 100.4 mAh g−1 with an operating voltage of ∼3.57 V (Na+/Na), but also exhibits excellent rate performance (∼86.7 mAh g−1 at 30 C) and cycle stability over 6000 cycles (capacity retention of 76.3%). Particularly, Na2.9Fe1.7(SO4)2.7(PO4)0.3 cathode still maintain its original crystal structural and sodium-storage property after exposure to air for one week. The high-voltage, long-life, and air-stable Na2.9Fe1.7(SO4)2.7(PO4)0.3 could be a competitive cathode candidate for low-cost sodium-ion batteries.

Synthesis and Properties of Polyvinylidene Fluoride-Hexafluoropropylene Copolymer/Li6PS5Cl Gel Composite Electrolyte for Lithium Solid-State Batteries.

Gel electrolytes for lithium-ion batteries continue to replace the organic liquid electrolytes in conventional batteries due to their advantages of being less prone to leakage and non-explosive and possessing a high modulus of elasticity. However, the development of gel electrolytes has been hindered by their generally low ionic conductivity at room temperature and high interfacial impedance with electrodes. In this paper, a poly (vinylidene fluoride)-hexafluoropropylene copolymer (PVdF-HFP) with a flexible structure, Li6PS5Cl (LPSCl) powder of the sulfur-silver-germanium ore type, and lithium perchlorate salt (LiClO4) were prepared into sulfide gel composite electrolyte films (GCEs) via a thermosetting process. The experimental results showed that the gel composite electrolyte with 1% LPSCl in the PVdF-HFP matrix exhibited an ionic conductivity as high as 1.27 × 10-3 S·cm-1 at 25 °C and a lithium ion transference number of 0.63. The assembled LiFePO4||GCEs||Li batteries have excellent rate (130 mAh·g-1 at 1 C and 54 mAh·g-1 at 5 C) and cycling (capacity retention was 93% after 100 cycles at 0.1 C and 80% after 150 cycles at 0.2 C) performance. This work provides new methods and strategies for the design and fabrication of solid-state batteries with high ionic conductivity and high specific energy.

In-situ formation of quasi-solid polymer electrolyte for wide-temperature applicable Li-metal batteries

As next-generation rechargeable batteries, the development of solid-state lithium-metal batteries (LMBs) in a multitude of applications is confronted with a trade-off between high energy density, safety, and wide-temperature tolerance. Especially in cold climates, their applications are challenged by insufficient dynamics in bulk electrolyte and at electrode/electrolyte interface. Herein, a flexible, highly ionic conductive, and low-temperature applicable quasi-solid polymer electrolyte (QSPE) is designed and fabricated, which achieves a stable Li-metal anode over a wide-temperature range (−20 ∼ 60 °C). The QSPEs prepared via in-situ polymerization of polyethylene glycol (PEO)-based monomers in low-melting solvent (1,3-dioxolane (DOL) or ethyl difluoroacetate (EDFA)) endow low-temperature tolerance, prominent ionic conductivity (4.5 × 10−4 S cm−1 at −20 °C) and exceptional electrochemical performance over a wide-temperature range. Consequently, with the DOL-based QSPE (D-QSPE), the Li/D-QSPE/LiFePO4 cell presents stable, long-term cycling at −20 °C (minimal capacity degradation over 550 cycles) and excellent fast-charging capacity (capacity retention of 81 % over 1300 cycles at 5 C). Even utilizing a thin lithium foil (25 μm) and a high mass loading LiFePO4 cathode (2.5 mAh cm−2), the assembled Li/LFP cell with a N/P ratio of 1.96 still exhibits good cycling performance at −20 °C. Additionally, the EDFA-based QSPE (E-QSPE) allows LMBs with NCM811 cathodes cycling over 140 cycles (capacity retention > 95 %) at −20 °C. With the capability of circumventing sluggish ion transport kinetics of quasi-solid polymer LMBs in cold climates, the developed polymer electrolyte provides new pathways for safe, high-capability, and wide-temperature operable batteries.

Hydrothermal synthesis of β-NiS layer structure nanoparticles for supercapacitor applications

At present, there is a significant research focus on development of sulfide based electrode materials for improving the performance of electrochemical supercapacitor (SC). Nickel sulfide (NiS) electrode materials has emerged attention as a promising candidate due to its high value of specific capacitance and outstanding redox activities. This study includes synthesis, characterization, and a novel electrode material called layer-like NiS that resembles a single-phase (β) is evaluated. At a current density of 3 mA g−1 in 3 M KOH electrolytes, the β-NiS electrode demonstrates an impressive specific capacitance of 780 F g−1 with 92 % cycling capacitance retention after 5000 cycles.