Superior Electrochemical Performance Research Articles

Photo-Crosslinked Polyurethane—Containing Gel Polymer Electrolytes via Free-Radical Polymerization Method

Using a novel technique, crosslinked gel polymer electrolytes (GPEs) designed for lithium-ion battery applications have been created. To form the photo crosslink via free-radical polymerization, a mixture of polyurethane acrylate (PUA), polyurethane methacrylate (PUMA), vinyl phosphonic acid (VPA), and bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) was exposed to ultraviolet (UV) radiation during the fabrication process. The unique crosslinked configuration of the membrane increased its stability and made it suitable for use with liquid electrolytes. The resulting GPE has a much higher ionic conductivity (1.83 × 10−3 S cm−1) than the commercially available Celgrad2500 separator. A crosslinked structure formed by the hydrophilic properties of the PUA-PUMA blend and the higher phosphate content from BMEP reduced the leakage of the electrolyte solution while at the same time providing a greater capacity for liquid retention, significantly improving the mechanical and thermal stability of the membrane. GPP2 shows electrochemical stability up to 3.78 V. The coin cell that was assembled with a LiFePO4 cathode had remarkable cycling characteristics and generated a high reversible capacity of 149 mA h g−1 at 0.1 C. It also managed to maintain a consistent Coulombic efficiency of almost 100%. Furthermore, 91.5% of the original discharge capacity was maintained. However, the improved ionic conductivity, superior electrochemical performance, and high safety of GPEs hold great promise for the development of flexible energy storage systems in the future.

Zinc cobaltite embedded in binary metal-organic frameworks using a direct binder-free electrode fabrication approach for efficient energy storage devices and monosodium glutamate detection

There is an imperative need to develop high performance electrode for advance energy storage devices. This work represents the successful synthesis of zinc cobaltite (ZnCo2O4), nickel cobalt metal organic framework, and their composite (ZnCo2O4@NiCo-MOF). The materials are synthesized by using both hydrothermal and sonication techniques. The ZnCo2O4 offers eco-friendly and diffusion regulated properties, while NiCo-MOF provides large specific surface area and tunable pore structure. The ZnCo2O4@NiCo-MOF provide superior electrochemical performance compared to ZnCo2O4 and NiCo-MOF in a three electrode setup. The ZnCo2O4@NiCo-MOF provides a specific capacity of 984 C/g at 1.5 A/g. The ZnCo2O4@NiCo-MOF is also utilized in two electrode setup with activated carbon. The ZnCo2O4@NiCo-MOF//AC device demonstrates the energy density of 92.4 Wh/kg and a power density of 930 W/kg. Additionally, the real time application of ZnCo2O4@NiCo-MOF electrode is also tested in the detection of monosodium glutamate in food. This study highlights the importance of ZnCo2O4@NiCo-MOF electrode materials for future storage and detection devices.

Amorphous Structure Benefits in MgV2O4/V2O3 Composites for Zinc-Ion Storage: An Integration of Computational and Experimental Studies.

This study investigates the electrochemical properties of MgV2O4/V2O3 composites for Aqueous Zinc-Ion Batteries (AZIBs) using both Density Functional Theory (DFT) calculations and experimental validation. DFT analysis reveals significant electron mobility and reactivity at the MgV2O4/V2O3 interface, enhancing Zn2+ storage capabilities. This theoretical prediction is confirmed experimentally by synthesizing a novel MgV2O4/V2O3 composite that demonstrates superior electrochemical performance compared to pristine phases. Notably, the transition of the MgV2O4/V2O3 composite into an amorphous structure during electrochemical cycling is pivotal, providing enhanced diffusion pathways and increased conductivity. The composite delivers a consistent specific capacity of 330.2 mAh g-1 over 50 cycles at 0.1 A g-1 and maintains 152.7 mAh g-1 at an elevated current density of 20 A g-1 after 2000 cycles, validating the synergy between DFT insights and experimental outcomes, and underscoring the potential of amorphous structures in enhancing battery performance.

A review on the development of metals-doped Vanadium oxides for zinc-ion battery

Rechargeable zinc-ion batteries (ZIBs) are emerging as promising energy storage devices for various applications, including large-scale energy storage, due to their environmental friendliness, enhanced safety, and low cost. A key challenge in ZIB development is creating cathode materials that reduce the solubility of active materials in aqueous electrolytes, increase electrical conductivity, and extend life cycles for high performance. Vanadium-based compounds, with their diverse structures and multiple oxidation states (+2, +3, +4, and +5), have been extensively studied as effective cathodes for ZIBs. This mini review highlights recent research on doping transition metals into vanadium oxide materials to achieve superior electrochemical performance compared to electrodes prepared via solid-phase synthesis and hydrothermal methods. Additionally, it offers guidance for the future development of vanadium-based materials.

Mechanochemically synthesized flower-like bismuth oxyhalides: An electrochemical platform for diclofenac detection

The emerging drug diclofenac (DICF) has been found to penetrates aquatic systems at alarming concentrations and poses serious and irreversible ecotoxicological threats around the world. In this work, we present the solid-state mechanochemical synthesis of 3D flower-like bismuth oxyhalides (BiOX, where X = Cl, Br, and I) as electrode materials for electrochemical detection of DICF. The characteristics of the flower-like BiOX are systematically investigated using spectroscopic and microscopic techniques. The BiOI-modified glassy carbon electrode (GCE) exhibits superior electrochemical performance for DICF detection compared to the pristine GCE, BiOCl/GCE, and BiOBr/GCE. The 3D flower-like architecture of BiOI facilitates favorable electrocatalytic activities due to its abundant electroactive sites, good conductivity, large surface area, and fast ion diffusion. Notably, the BiOI/GCE displays wide linear ranges (0.5–11.3 & 11.3−76), a low limit of detection (0.11 μM), high sensitivity (1.33 μA μM–1 cm–2), excellent repeatability (2.91 %), good reproducibility (2.88 %), and anti-interfering ability (<±5 %). To validate the practicality of the fabricated BiOI/GCE, the quantitative detection of DICF in human urine and river water is demonstrated and achieves acceptable recovery values. This study introduces an innovative approach to design and produce electrode materials with distinct properties, enabling enhanced electrocatalysis for various electrochemical sensing applications.

Tuning the Properties of Halide Nanocomposite Solid Electrolytes with Diverse Oxides for All-Solid-State Batteries.

Herein, we report halide nanocomposite solid electrolytes (HNSEs) that integrate diverse oxides with alterations that allow tuning of their ionic conductivity, (electro)chemical stability, and specific density. A two-step mechanochemical process enabled the synthesis of multimetal (or nonmetal) HNSEs, MO2-2Li2ZrCl6, as verified by pair distribution function and X-ray diffraction analyses. The multimetal (or nonmetal) HNSE strategy increases the ionic conductivity of Li2ZrCl6 from 0.40 to 0.82 mS cm-1. Additionally, cyclic voltammetry test findings corroborated the enhanced passivating properties of the HNSEs. Notably, incorporating SiO2 into HNSEs leads to a substantial reduction in the specific density of HNSEs, demonstrating their strong potential for achieving a high energy density and lowering costs. Fluorinated SiO2-2Li2ZrCl5F HNSEs exhibited enhanced interfacial compatibility with Li6PS5Cl and LiCoO2 electrodes. Cells employing SiO2-2Li2ZrCl5F with LiCoO2 exhibit superior electrochemical performance delivering the initial discharge capacity of 162 mA h g-1 with 93.7% capacity retention at the 100th cycle at 60 °C.

Tailoring Sb-F doped ZnO nanoparticles for dual-functionality: Photocatalytic and supercapacitor applications

In the present work, pure zinc oxide nanoparticles (ZnO NPs), antimony doped ZnO nanoparticles (Sb-ZnO NPs), fluorine doped ZnO nanoparticles (F-ZnO NPs), and antimony and fluorine co-doped ZnO nanoparticles (Sb/F-ZnO NPs) with various dopant concentrations are synthesized by co-precipitation method. The optical, structural, morphological, photocatalytic, and electrochemical activities of ZnO nanostructures by the influence of Sb and F doping were investigated. XRD showed crystallite size decreased with increasing Sb/F content, while BET showed 64.25 m2/g surface area for ZnO-5 %Sb-10 %F. SEM and TEM images suggesting Sb/F doping changed the ZnO morphology from spherical to bricks-built and nanorod-built flower structures. XPS verified Sb (+3) and F (−1) oxidation states, while absorption spectroscopy showed increased energy bandgap with 5 % Sb and 10 % F doping in ZnO. The photocatalytic activity for mixture of congo red, rhodamine B, and methylene blue are closer to real polluted water. All the samples exhibited good photocatalytic activity for the mixture with degradation efficiency reaching to 99 %. At a constant current density of 1 A/g, symmetric supercapacitors utilizing Sb/F-ZnO electrodes exhibited a specific capacitance of 762 Fg−1, underscoring their superior electrochemical performance and potential for advancing energy storage technologies. Further, physiochemical and electrochemical properties of ZnO can be perfectly tuned by the optimal setting for co-doping in ZnO up to 5 % Sb and 10 % F by the co-precipitation approach

Microwave-assisted sol-gel synthesis of MFe2O4@SiO2 (M = Cu, Ni, Co) ceramic nanostructures using rice husk as a sustainable precursor for electrochemical energy storage

In this study, we report the synthesis of MFe2O4@SiO2 (M = Cu, Ni, Co) nanostructures by microwave-assisted sol-gel synthesis utilizing rice husk as a cost-effective silica precursor and polyethylene glycol (PEG) as a soft template. Structural and electrochemical properties were characterized using XRD, FTIR, FESEM, EDS, HRTEM, BET, and electrochemical techniques. The result revealed the formation of well-defined MFe2O4 spherical nanoparticles decorated mesoporous silica spheres. Electrochemical studies indicate that the CoFe2O4@SiO2 electrode performs better than the CuFe2O4@SiO2 and NiFe2O4@SiO2 electrodes in faradaic redox processes and supercapacitor performance, having a specific capacitance of 1263 F/g at 1 A. Asymmetric supercapacitor (ASC) with CoFe2O4@SiO2 as positive electrode exhibits high specific capacitance of 135.66 F/g at 1 A/g with good cycle stability retention (70.83 % at 10 A/g), high energy density (50.4 Wh/kg) and power density (891.522 W/kg). CoFe2O4@SiO2 performs better than CuFe2O4@SiO2 and NiFe2O4@SiO2 because cobalt ferrite (CoFe2O4) has higher electrical conductivity, superior redox activity, and better electrochemical stability. This study offers cost-effective potential electrode materials for electrochemical energy storage, combining environmental sustainability with superior electrochemical performance.

Boosting the capacitive property of binary metal tellurium of MnCoTe/NiFeTe yarn coils-like through surface engineering for high-performance supercapacitors

Improving the performance of electrode materials based on transition metals can significantly push advancements in energy storage devices. In this work, we offer a novel in situ tellurization approach to synthesize brand-new decorated yarn-coils MnCoTe/NiFeTe on a NiF (labeled MCTe/NFTe@NiF) which makes them attractive candidates for electrode materials in hybrid supercapacitors. At first, two consecutive hydrothermal methods were used to create electrode materials MnCo-LDH and MnCo-LDH/NiFe-LDH on nickel foam, respectively. In the following, electrode material MnCo-LDH/NiFe-LDH was subjected to a tellurization process to create MnCoTe/NiFeTe nanostructures. The direct growth strategy of electrode materials on a conductive substrate (NiF) effectively eliminates the need for polymer binder or conductive materials, thereby facilitating the redox process. The MnCoTe/NiFeTe@NiF electrode benefits from the synergistic effects of conductive tellurium and yarn coils-like morphology, resulting in faster electron/ion transport, increased efficiency, and superior electrochemical performance. The MCTe/NFTe@NiF electrode reveals highly desirable electrochemical characteristics, including a specific capacity of 223.36 mA h/g at 1 A/g, and reliable longevity surpassing 10,000 GCD cycles, with maintaining 73.18 % of its initial specific capacity at 30 A/g. We have prepared a hybrid supercapacitor (labeled MCTe/NFTe@NiF(+)//AC@NiF(−)), which utilizes the positive MCTe/NFTe@NiF and the negative AC@NiF electrodes. This hybrid supercapacitor indicated an excellent energy density of 51.55 Wh/kg, a power density of 799.98 W/kg, and showed substantial longevity (92.33 % after 10,000 GCD cycles).

Facile Biogenic synthesis of Europium doped lanthanum silicate nanoparticles as novel supercapacitor electrodes for efficient energy storage applications

In this work, we demonstrated for the first time, use of Europium doped lanthanum silicate nanoparticles (LS NPs) as electrodes for supercapacitor applications. Europium (Eu3+) doped (5 mol%) LS NPs were synthesized by green solution combustion method using Mexican mint leaf extracts. Various analytical techniques such as High-Resolution Transmission Electron Microscopy (HRTEM), Selected Area Diffraction (SAED), Powder X-ray Diffraction (PXRD), Fourier Transform Infra-Red Spectroscopy (FTIR) and Diffuse Reflectance Spectroscopy (DRS) techniques were used to confirm the morphological and structural characteristics of the synthesized nanoparticles. The HRTEM and SAED patterns confirms the formation of NPs having agglomerated structure with a particle size less than 50 nm. The PXRD patterns reveals crystalline cubic structure for the NPs. Further, the FT-IR spectra reveal the successful doping of Europium in Lanthanum Silicate NPs. The DRS (Diffuse Reflectance Spectroscopy) studies confirm the reduced band gap for Europium (Eu3+) doped (5 mol%) LS NPs. Cyclic voltametric and electrochemical impedance spectroscopy experiments were performed in an alkaline medium to compare the electrochemical activity of Eu3+ doped LS NPs with that of their undoped counterpart. The Eu3+ doped (5 %) LS NPs electrodes attained a specific capacitance of 373.3 Fg-1 at a current density of 0.5 Ag-1 in comparison to pure LS NPs which is about 267 Fg-1. The long-term stability of the Eu3+ doped (5 %) LS NPs electrodes show excellent stability up to 4000 cycles of operation in comparison pure LS NPs electrodes. Doping of Eu3+ had a favourable effect on the conductivity and electrochemical activity of LS NPs. Due to favourable green combustion synthesis, superior electrochemical performance, these Eu3+ doped LS NPs could be potential materials for new generation supercapacitors in energy storage applications.

Multicomponent Hierarchical Cu-based Advanced Cathode for Ultrahigh Capacity Rechargeable Cu-Zn Battery

Rechargeable aqueous Zn-based batteries (RAZBs) have emerged as a practically attractive option for large-scale energy storage applications due to their cost-effectiveness, safety, eco-friendliness, and high theoretical capacity. Nonetheless, the application of RAZBs at the grid scale is restricted by the drawbacks of cathode that exhibit low capacities and poor durability. In this work, a multicomponent hierarchical Cu@CuO@Cu2O cathode with superior electrochemical energy storage performance has been successfully synthesized by a fairly simple calcination method. Benefiting from its large active area, fast ion diffusion channel, high conductivity, and synergetic effect between different components, the resulting Cu@CuO@Cu2O electrode exhibits ultrahigh specific capacity (40.2 mAh cm-2, 402 mAh cm-3 at 10mAcm-2), excellent rate capability (24.8 mAh cm-2, 248 mAh cm-3 at 100mAcm-2) and satisfactory cycling durability (71.5% capacity retention after 3800 cycles). To our knowledge, such high areal/volumetric specific capacity ranks top among previously reported Cu-based electrode and other aqueous electrodes. Furthermore, the fabricated Cu@CuO@Cu2O//Zn battery achieves an extraordinary energy density of 24.5 mWh cm-2 and a remarkable cyclic capability of 91% capacity retention after 3000 cycles, highlighting its potential for large-scale energy storage in RAZBs.

Unravelling the anionic stability of an ether-based electrolyte with a hard carbon or metallic sodium anode for high-performance sodium-ion batteries

In hard carbon (HC) anodes, elucidating the relationship between the solid electrolyte interphase formation and the solvated Na+ co-intercalation mechanism is crucial, particularly considering different anionic salts in ether-based electrolytes. Here, we comprehensively explore the impact of different anionic salts on the electrochemical performance of HC/Na half-cell and elucidate the underlying mechanism through experimental studies and theoretical calculations. The surface morphology of the HC anode and its interphasial property are further investigated to evaluate the differences endowed by the presence of various anionic salts in diglyme (2G). The HC/Na half-cells with NaPF6-2G and sodium trifluoromethanesulfonate (NaCF3SO3)-2G display superior electrochemical performance with faster kinetics and lower interfacial resistance than those with NaClO4-2G, sodium bis-(fluorosulfonyl) imide (NaFSI)-2G and sodium bis-(trifluoromethanesulfonyl) imide (NaTFSI)-2G. NaClO4-2G forms a relatively thick interphase layer with high resistance at the electrode/electrolyte interface owing to its insufficient stability. NaFSI-2G and NaTFSI-2G exhibit severe side reactions with Na metal, producing a thick interphase layer on the HC surface with high interfacial resistance from excess electrolyte decomposition, thus deteriorating the electrochemical performance. In summary, the study on the stability of different anionic salts in ether-based electrolyte for the HC anode with the intercalation mechanism provides valuable insights for screening appropriate conductive salts for high-performance sodium-ion batteries, especially when considering Na metal counter/reference electrodes.

Attaining Superior Performance in an Aqueous Hybrid Supercapacitor Based on N-Doped Highly Porous Carbon Spheres and N-S Dual Doped Co3O4

Cobalt oxide (Co3O4) has seen a significant interest for its application as an electrode for supercapacitors, due to its cost-effectiveness, high theoretical capacitance and outstanding redox activity. However, Co3O4 exhibits poor electrical conductivity and cycle life restricting its high-power energy storage applications. High porosity carbons are materials of choice for applications in electric double layer charge storage but suffer from poor energy densities due to limited charge storage capabilities. Here we propose a hierarchical functionalization strategy to develop N, S co-doped Co3O4 and N doped high porosity carbon micro-spheres for efficient and durable hybrid supercapacitor. Benefiting from the structural eminence, improved electrical conductivity and high quantity of N content, the heteroatom enriched N, S co-doped Co3O4 and N doped porous carbon spheres demonstrates superior electrochemical performance. Moreover, hybrid supercapacitor cell with N, S co-doped Co3O4 as a cathode and N doped porous carbon spheres as anode deliver a high specific energy of 52 Wh kg-1 at power density of 1462 W kg-1 coupled with the capacity retention of 95% after 5,000 charge-discharge cycles.Therefore, by improving both anode and cathode simultaneously can be considered an effective approach to enhance energy storage capabilities of hybrid supercapacitors while maintain exceptionally high-power densities.

Enhanced charge storage in supercapacitors using carbon nanotubes and N-doped graphene quantum dots-modified (NiMn)Co2O4

The integration of ternary metal oxides into carbon materials is anticipated to significantly boost the electrochemical performance of supercapacitor electrodes. This article synthesized carbon nanotubes (CNT)/(NiMn)Co2O4 composite materials using a straightforward hydrothermal method and subsequently prepared composite thin films of CNT/P-(NiMn)Co2O4@NGQD by phosphating and incorporating nitrogen-doped graphene quantum dots (NGQD). These films served as the functional electrode material for supercapacitors, enhancing their performance capabilities. The specific capacity of CNT/P-(NiMn)Co2O4@NGQD was measured at 2172.0 F g−1 at a current density of 1 A g−1, maintaining a capacitance of 1954.0 F g−1 at 10 A g−1, thus demonstrating excellent rate performance. Electrochemical impedance spectroscopy (EIS) further revealed enhancements in electrolyte flow dynamics and capacitance behavior post-NGQD introduction. The energy density of the composite material reached 94.4 Wh kg−1 at power density of 800 W kg−1, demonstrating superior electrochemical performance. The enhancement in these electrochemical properties is attributed to the high specific surface area and active sites of CNT/P-(NiMn)Co2O4@NGQD films, along with the synergistic effects of NGQD and metal ions facilitating rapid electrons and charge transfer. This work provides new insights into developing high-performance supercapacitors.

Synergistic Triple-Action morphological composite Anode: Integrating lattice Softening, Interfacial electric Fields, and dual confinement for superior Potassium-Ion battery performance

Synergistic effects could significantly improve slow redox kinetics and structural pulverization of electrodes in potassium ion batteries (PIBs); however, the performance of single synergistic designs is limited. Multi-synergistic composite, shaped by a blend of factors, substantially boosts performance, yielding outcomes that surpass single synergistic coupling design. Herein, we develop a Bi2Se3/Sb2Se3@NC@G electrode that integrates three key features for enhanced potassium-ion storage: p-n junctions enhance electron transfer through internal electric fields, dual confinement prevents K2Se dissolution into the electrolyte, and lattice softening in the Bi-Sb alloy relieves stress during potassium ion insertion/extraction. These multi-synergistic effects enable the heterostructure to exhibit superior electrochemical performance in potassium-ion batteries.The Bi2Se3/Sb2Se3@NC@G electrode demonstrates notable capacity of 640 mA h/g at current density of 50 mA/g, achieving 95.5 % of its theoretical capacity, maintain stable capacity of 310 mA h/g after 5000 cycles at current density of 0.5 A/g with 0.002 % per cycle degradation, and exhibits the fastest rate capability up to 10 A/g (172 mA h/g). Furthermore, potassium ion hybrid capacitor (PIHC) can achieve a high energy density of 118 Wh kg−1 and a power density of 5200 W kg−1, and full cell shows an attractive energy density of 97 Wh kg-1 and a stable performance after 250 cycling number under 1 A/g. This study proposes an effective strategy that employs multiple synergistic coupling designs to maximize potassium-ion storage capacity, achieving a breakthrough in extending battery lifecycle.

Electrode engineering strategies for boosting the performance of Ni Co Al − LDH in supercapacitor application

In recent years, the search for efficient electrode materials for supercapacitors has focused on improving operating voltage thereby specific energy. This study explores NiCoAl layered double hydroxides (LDHs) as electrode materials, synthesized with varying Ni ratios (x = 0.25, 0.5, 0.75) through a hydrothermal method. The NCAL13 variant demonstrated superior electrochemical performance, achieving a specific capacitance of 1413F/g and retaining 77 % capacitance after 5000 cycles. An asymmetric cell using NCAL13 and activated carbon delivered 150F/g and an energy density of 50.1 Wh/kg, retaining 86 % capacitance after 10,000 cycles, highlighting its potential for supercapacitor applications.

Electronically Conductive Polymer Enhanced Solid-State Polymer Electrolytes for All-Solid-State Lithium Batteries

All-solid-state lithium batteries (ASSLBs) have gained enormous interest due to their potential high energy density, high performance, and inherent safety characteristics for advanced energy storage systems. Although solid-state ceramic (inorganic) electrolytes (SSCEs) have high ionic conductivity and high electrochemical stability, they experience some significant drawbacks, such as poor electrolyte/electrode interfacial properties and poor mechanical characteristics (brittle, fragile), which can hinder their adoption for commercialization. Typically, SSCE-based ASSLBs require high cell stack pressures exerted by heavy fixtures for regular operation, which can reduce the energy density of the overall battery packages. Polymer–SSCE composite electrolytes can provide inherently good interfacial contacts with the electrodes that do not require high cell stack pressures. In this study, we explore the feasibility of incorporating an electronically and ionically conducting polymer, polypyrrole (PPy), into a polymer backbone, polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), to improve the ionic conductivity of the resultant polymer–SSCE composite electrolyte (SSPE). The electronically conductive polymer-incorporated composite electrolyte showed superior room temperature ionic conductivity and electrochemical performance compared to the baseline sample (without PPy). The PPy-incorporated polymer electrolyte demonstrated a high resilience to high temperature operation compared with the liquid-electrolyte counterpart. This performance advantage can potentially be employed in ASSLBs that operate at high temperatures. In our recent development efforts, SSPEs with optimal formulations showed room temperature ionic conductivity of 2.5 × 10−4 S/cm. The data also showed, consistently, that incorporating PPy into the polymer backbone helped boost the ionic conductivity with various SSPE formulations, consistent with the current study. Electrochemical performance of ASSLBs with the optimized SSPEs will be presented in a separate publication. The current exploratory study has shown the feasibility and benefits of the novel approach as a promising method for the research and development of next-generation solid composite electrolyte-based ASSLBs.

Electrodeposited multiphase Sb, SbSn, Cu2Sb composite with superior chemical buffering as negative electrode for lithium-ion batteries: Effect of composition on lithiation behavior of Sb-Sn-Cu alloys

Antimony-tin ternary alloys outperform graphite as negative electrodes for lithium-ion batteries, offering significantly higher gravimetric and volumetric capacities. These alloys, conductive without additives, can be electrodeposited without binders, enhancing cell design and capacity. Based on bath composition, Sn-rich or Sb-rich SbSnCu ternary alloys can be synthesized which undergoes active-active-inactive chemical buffering during lithiation. The Sb-rich alloys show better stress buffering due to more lithiation/delithiation peaks and better use of lithium-inactive copper. This study finds Sb-rich alloys exhibit superior structural stability and electrochemical performance, delivering 374 mAh g−1 at 200 mA g−1 after 100 cycles, while Sn-rich alloys show substantial capacity fading, retaining only 113 mAh g−1. The Sb-rich alloy maintains structural integrity, losing only 20 % capacity over the last 80 cycles, compared to 48 % loss in capacity during the 50–80th cycles in Sn-rich alloys.

Tuning capacitance of bimetallic ZnCo2O4 using anionic, cationic and non-ionic surfactants by hydrothermal synthesis for high-performance asymmetric supercapacitor

Surface properties of nanomaterials are directly related to their electrochemical performance, with surfactants playing an essential role in their cost-effective synthesis as structure-directing agents and templates. This research article discusses the effects of neutral, cationic, and anionic surfactants on the capacitance of bimetallic ZnCo2O4 nanomaterial, synthesized via a straightforward hydrothermal-annealing method. We investigated how cationic (cetyl-trimethyl ammonium bromide), anionic (sodium dodecyl sulphate), and non-ionic (urea) surfactants influence the electrochemical characteristics of ZnCo2O4 nano-powders. All three surfactant-based ZnCo2O4 electrodes exhibited Faradaic behaviour during electrochemical tests. The ionic nature of the surfactants significantly impacted the charge-storage mechanism, with specific capacitance values rising in the order of Urea (550 Fg−1) < C-TAB (740 Fg−1) < SDS (980 Fg−1) at a 1 Ag−1 in half-cell studies. The ZnCo2O4-SDS displayed the highest surface redox reactivity and superior electrochemical performance, with 426 Fg−1 in full-cell studies, energy density of 230 WhKg−1 (1 Ag−1), power density of 18,213.9 WKg−1 (10 Ag−1), and 93 % capacitance retention is observed over 50,000 cycles (50 Ag−1).

SILAR synthesized α-Fe2O3 thin film anode for the development of all binder-free, high-performing Mg-ion asymmetric supercapacitors

Divalent-ion electrolyte-based supercapacitors (D-ISCs) have been gaining prominence due to their affordability and potential to deliver superior electrochemical performance as compared to single-ion electrolyte-based supercapacitors. Moreover, to satisfy the high energy demands of advanced electronic devices, a rational combination of electrodes and electrolytes in D-ISCs is required to enhance their power and energy densities further. Therefore, the present work describes the development of all binder-free magnesium-ion supercapacitor (Mg-ISC) using α-Fe2O3 as an anode and MnO2 thin films as a cathode. The binder-free thin films are fabricated using the SILAR method, allowing for direct formation of uniform and nanocrystalline thin films on the substrate, confirmed through structural and morphological analysis. Individually, both α-Fe2O3 and MnO2 thin film electrodes employed as anode and cathode exhibit excellent electrochemical properties, achieving a specific capacitance (Csp) of 381 F g−1 and 587 F g−1 at 0.2 mA cm−2, respectively, and confirms that both electrodes can be effective and reversible host materials. Furthermore, the developed Mg-ISC delivers a remarkable Csp of 234 F g−1 at a current density of 0.2 mA cm−2. Moreover, the aqueous Mg-ISC achieves a significant energy density of 105.2 Wh kg−1 at a high-power density of 619.4 W kg−1, suggesting that the device can deliver both high energy and power simultaneously. Moreover, Mg-ISC retained 86 % of its capacitance through 10,000 cycles at 5 mA cm−2. The current work lays the basis for developing D-ISC that are safe, sustainable, and provide improved electrochemical performance for a wide range of applications.