High Specific Capacitance Research Articles

Trace Selenium Doping for Improving the Reaction Kinetics of ZnS Cathode for Aqueous Zn-S Batteries.

Aqueous Zinc-sulfur (Zn-S) batteries are promising for the field of energy storage due to their low cost, high theoretical capacity, and safety. However, the large volume expansion and the inherently poor conductivity of sulfur would result in electrode cracking and sluggish reaction kinetics, limiting the practical application of Zn-S batteries. Herein, commercial zinc sulfide (ZnS) is employed instead of S as cathode and proposed a doping modification strategy to solve the above problems. The designed ZnS0.93Se0.07 cathode shows good cycle stability and much-improved reaction kinetics, which is due to the smaller bandgap of ZnS0.93Se0.07 (1.40eV) compared to ZnS (1.86eV). As a result, the obtained ZnS0.93Se0.07 cathode exhibits a high specific capacity of 552 mAh g-1 (1672.6 mAh g-1 based on S) at 0.1 A g-1 and 330 mAh g-1 (1000 mAh g-1 based on S) at 2 A g-1. Moreover, the ZnS0.93Se0.07 cathode can provide a high areal capacity of 3.8 mAh cm-2 at a high mass loading of 10mg cm-2 and limited electrolyte (4µL mg-1). This work provides a simple and effective cathode modification strategy, which is conducive to promoting the practical application of Zn-S batteries.

Microwave synthesis of magnesium phosphate-rGO as an effective electrode for supercapacitor application

Abstract Transition metal phosphate based materials is being used for energy storage because of P–O covalent bond which facilitates more storage compared to other transition metals and this covalent bond enhanced the electrochemical performance for supercapacitor applications. Pure magnesium phosphate (Mg3(PO4)2) were synthesized via microwave synthesis as the composite varies with rGO (MgPO-XrGO) X=25,50,75,100mg. The prepared composite materials were examined employing XRD, Raman, FT-IR, SEM and XPS studies. Electrochemical studies (CV, EIS, GCD) of three electrode system for the prepared electrodes were performed using Biologic SP-150 with 2M (H2SO4) as electrolyte. From the XRD results, triclinic structured MgPO was confirmed (JCPDS card #35–0329) and rGO has enhanced the crystallinity of MgPO composite. From Raman analyses, the well graphitization nature of rGO in composite MgPO was identified and from XPS analysis chemical composition of the elements was analyzed. The FT-IR fundamental modes of vibrations of PO 4 3 − ${\text{PO}}_{4}^{3-}$ (γ 1,γ 3,γ 4) were obtained. The electrochemical analysis of the prepared material such as pure and composite materials showed better performance. The high specific capacitance was obtained for MgPO-50rGO because MgPO has high coordination with rGO. As Mg2+ oxidation state has high chemical reactivity compared to other earth metals and other advantage is P–O covalent bond that enhanced the performance of the electrode. By facilitating these advantages, rGO is included as composite to develop the electrode to favor the practical applications. By using the optimum level rGO composite with MgPO4-50rGO a better new candidate was successfully developed for supercapacitor applications. The fabricated MgPO-50rGO//Activate carbon full cell set up exhibited the specific capacitance 61 Fg−1 at 1 Ag−1, 21.7 Wh kg−1 energy density and 790.0 W kg−1 power densities and explored outstanding capacitive retention in 2 electrode full cell setup cyclic stability of 99.1 % over the 5000 cycles.

Amorphous lithiophilic cobalt‐boride@rGO interlayer for dendrite‐free and highly stable lithium metal batteries

AbstractLithium metal batteries (LMBs) are recognized to be crucial for secondary battery technology targeting electric vehicles and portable electronic devices. However, the undesirable growth of lithium dendrites would result in reduced capacity, short‐circuit, and overheating, seriously hindering the practical applications of LMBs. To address this issue, a neoteric lithiophilic interlayer on a commercial polypropylene separator is presented for the first time, which is constructed by amorphous CoB nanoparticles decorated reduced graphene oxide nanosheets (CoB@rGO). Density Functional Theory calculations and experimental analysis reveal remarkable lithiophilicity features for CoB@rGO and provide multiple Li deposition sites and improved electrolyte wettability, which facilitates the formation of durable solid electrolyte interphase (SEI), reduces side reactions, and improves Li+ flux regulation for long‐term cycling stability in LMBs. Taking advantage of these merits, the symmetric Li//Li cell with CoB@rGO/PP separator exhibits stable cycling for up to 1600 h at 1 mA cm−2 with 1 mAh cm−2. Employed with CoB@rGO separator, the Li//LiFePO4 full cell with a high LiFePO4 loading of 11 mg cm−2 delivers a high initial specific capacity of 115.3 mAh g−1 and a low decay rate of 0.08% per cycle after 200 cycles even at a high rate of 2C.

Characterization and antibacterial studies of Sn doped CuO nanocomposite using centratherum punctatum leaf extract

In order to synthesize CuO, SnO2, and Sn doped CuO nanocomposites, accessible and non-toxic materials, specifically leaf extract from Centratherum punctatum, were used in this work to apply the concepts and practices of green chemistry. These methods are both economical and environmentally friendly. A comprehensive range of characterisation techniques, including as FTIR, X-ray diffraction, and UV-vis spectroscopy, were also used to confirm the structures of all the produced nanomaterials. Instead, FESEM and EDAX were used to analyze the morphologies and elemental composition of recently produced nanomaterials. A decline in the optical band gap values was indicated by the red shift observed in the UV-vis study following tin doping. A sample's presence of different functional groups is confirmed by FT-IR analysis. For CuO NPs, SnO2, and Sn doped CuO NCs, the XRD results yielded crystallite sizes of 6 nm, 21 nm, and 29 nm, respectively, for the produced particles. The ferromagnetic, diamagnetic, and super paramagnetic characteristics of the produced samples at room temperature were validated by vibrating sample magnetometer experiments. Cyclic voltammetry is used to examine the nanoparticles' electrochemical analysis. Using Sn doped CuO nanocomposite material, it shows a high specific capacitance value of about ~187 Fg-1 at a current density of 10 mV/s. It was found from the electrochemical studies that the produced nanomaterials are suitable for capacitive behaviour. After all, the presence of inhibition zones surrounding each well led us to the conclusion that the nanoparticles exhibited antibacterial activity against the pathogenic strains of Staphylococcus aureus and Escherichia coli.

Relay-Type Catalysis by a Dual-Metal Single-Atom System in a Waste Biomass Derivative Host for High-Rate and Durable Li-S Batteries.

An environmental-friendly and sustainable carbon-based host is one of the most competitive strategies for achieving high loading and practicality of Li-S batteries. However, the polysulfide conversion reaction kinetics is still limited by the nonuniform or monofunctional catalyst configuration in the carbon host. In this work, we propose a catalysis mode based on "relay-type" co-operation by adjacent dual-metal single atoms for high-rate and durable Li-S batteries. A discarded sericin fabric-derived porous N-doped carbon with a stacked schistose structure is prepared as the high-loading sulfur (84 wt %) host by a facile ionothermal method, which further enables the uniform anchoring of Fe/Co dual-metal single atoms. This multifunctional host enables superior lithiophilic-sulfiphilic and electrocatalytic capabilities contributed by the "relay-type" single-atom modulation effects on different conversion stages of liquid polysulfides and solid Li2S2/Li2S, leading to the suppression of the "shuttle effect", alleviation of nucleation and decomposition barriers of Li2Sx, and acceleration of polysulfide conversion kinetics. The corresponding Li-S batteries exhibit a high specific capacity of 1399.0 mA h g-1, high-rate performance up to 10 C, and excellent cycling stability over 1000 cycles. They can also endure the high sulfur loading of 8.5 mg cm-2 and the lean electrolyte condition and yield an areal capacity as high as 8.6 mA h cm-2. This work evidentially demonstrates the potential of waste biomass reutilization coupled with the design of a single-atom system for practical Li-S batteries with high energy density.

Electropolymerization of a Carbonyl-Modified Dihydropyrazine Derivative for Aqueous Zinc Batteries with Ultrahigh Cycling Stability.

The design of aqueous zinc-ion batteries (ZIBs) that have high specific capacity and long-term stability is essential for future large-scale energy storage systems. Cathode materials with extended π-conjugation and abundant active sites are desirable to enhance the charge storage performance and the cycling stability of the aqueous ZIB. Based on this concept, 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetrone was chosen as the monomer to be electropolymerized onto carbon cloth (PDHPQ-Tetrone/CC). When used as the cathode material for aqueous ZIBs, an exceptional cycling life (>20,000 cycles) at a current density of 10 A g-1 was achieved, with the specific capacity maintained at 82.8% and with the Coulombic efficiency at around 100% throughout cycling. At the charge-discharge current density of 0.1 A g-1, the ZIB with PDHPQ-Tetrone/CC achieved a high specific capacity of 248 mAh g-1. Kinetic analyses showed that both surface-capacitive-controlled processes and semi-infinite diffusion-controlled processes contribute to the stored charge. The charge storage mechanism was investigated with ex situ characterizations and involves the redox processes of carbonyl/hydroxyl and amino/imino groups coupled with insertion and extraction of both Zn2+ and H+.

Gas-Phase-Induced Engineering for Fabrication of 3D Hierarchical Porous Nickel and Its Application toward High-Performance Supercapacitors.

Commercial nickel foam (NF), which is composed of numerous interconnected ligaments and hundred-micron pores, is widely acknowledged as a current collector/electrode material for catalysis, sensing, and energy storage applications. However, the commonly used NF often does not work satisfactorily due to its smooth surface and hollow structure of the ligaments. Herein, a gas-phase-induced engineering, two-step gaseous oxidation-reduction (GOR) is presented to directly transform the thin-walled hollow ligament of NF into a three-dimensional (3D) nanoporous prism structure, resulting in the fabrication of a unique hierarchical porous nickel foam (HPNF). This 3D nanoporous architecture is achieved by utilizing the spontaneous reconstruction of nickel atoms during volume expansion and contraction in the GOR process. The process avoids the involution of acid-base corrosion and sacrificial components, which are facile, environmentally friendly, and suitable for large-scale fabrication. Furthermore, MnO2 is electrochemically deposited on the HPNF to form a supercapacitor electrode (HPNF/MnO2). Because of the fully open structure for ion transport, superhydrophilic properties, and the increased contact area between MnO2 and the current collector, the HPNF/MnO2 electrode exhibits a high specific capacitance of 997.5 F g-1 at 3 A g-1 and remarkable cycling stability with 99.6% capacitance retention after 20000 cycles in 0.1 M Na2SO4 electrolyte, outperforming most MnO2-based supercapacitor electrodes.

Multiple phase transformation of ZIF-L to LDH and Ag nanoparticles decorated on CoNi layered double hydroxides for high-performance supercapacitor and highly efficient hydrogen evolution reaction

ZIF-L-derived binary layered double hydroxide (LDH) established active catalysts have been shown to have potential as electrode materials in the development of high-performance supercapacitors (SCs) and hydrogen evaluation reactions (HER). This study uses conductive nano-silver (Ag) particles in hierarchically integrated CoNi-LDH nanosheets (NSs), which are described. The developed Ag@CoNi-LDH NSs electrode has a very high specific capacitance of 2878 F g−1 at 0.5 A g−1 and an impressive rate capability. This is due to consistent morphology, plentiful electroactive sites, homogeneous particle size, and decreased electronic/ionic impedance. The fabrication of solid-state hybrid supercapacitors (HSCs) using Ag@CoNi-LDH NSs as the positive electrode and activated carbon (AC) as the negative electrode in PVA/KOH polymer gel electrolytes has been described. The prepared supercapacitors achieve a maximum energy density of 105 Wh kg−1 at power densities of 1183 Wh kg−1, coupled with excellent initial capacitance retentions of 97 % after 20,000 cycles. Ag@CoNi-LDH NSs demonstrate effective electrocatalytic activity towards HER with an ultra-low overpotential of 26 mV at 10 mA cm−2 and the associated Tafel value of 35 mV dec−1 using 0.5 M acidic electrolyte. It is possible to attribute the extraordinary electrochemical performance to the thoughtful mixture of two electroactive materials in the future.

High loading electrode with superior electron/ion transport network for high performance lithium-ion batteries

High loading electrode design is beneficial to increase the energy density of lithium ion batteries. Two obstacles for the high loading electrode application should be removed, including the limitation on ion/electron transport within high loading electrode and the structure stability. Here, the electron conduction on LiNi0.8Co0.1Mn0.1O2 cathodes is enhanced with evenly and tightly Ketjen Black coating via high-speed dry mixing, while carbon nanotube is added to enhance the electron conduction between LiNi0.8Co0.1Mn0.1O2 particles, thus to construct three-dimensional electron migration channel. In addition, the large amount of electrolyte adsorbed by porous Ketjen Black and carbon nanotube enhances the Li+ ion diffusivity in this network. As a result, LiNi0.8Co0.1Mn0.1O2 electrode with only 1 % Ketjen Black and 3 % carbon nanotube can achieve both high electron/Li+ ion diffusivity and high parking density (2.2 g cm−3). A thick electrode with an areal mass loading of 20 mg cm−2 shows a high specific capacity of 111.2 mA h g−1 at 4 C and capacity retention rate of 98.2 % after 100 cycles at 2 C.

Order-disorder structural engineering of vanadium oxide anode: Balancing ionic and electronic dynamic for fast-charging aqueous Li-ion battery

Fast-charging aqueous lithium-ion batteries (ALIBs) are considered as promising energy storage devices because of their non-flammability and environmentally friendly characteristics. However, how to balance the ionic and electronic dynamics for fast charging reactions remains a significant challenge under the current research status. Here, the order-disorder structural engineering strategy is adopted to resolve this issue, considering the difference between ion and electron transportation in the crystalline and amorphous phases, respectively. Vanadium oxide anodes were developed with optimized ionic and electronic dynamics by using an organic-inorganic hybrid material as a precursor along with refined regulation on the calcination temperature and time. This facile and large-scale extendable approach harnesses the benefits of the order-disorder structure to optimize Li+ storage efficiency and facilitate the high reversibility of Li-ion during fast charging. Consequently, the order-disorder V2O5-based full cell with LiMn2O4 as a cathode exhibits high specific capacity (262.71 mAh g−1, 89.35 % of the theoretical capacity of V2O5), high energy density (166.04 Wh kg−1), fast Li-ion diffusion coefficient (7.34×10−5 cm2 s−1) and fast-charging performance (only 6 min achieves 82.84 % of initial state-of-charge capacity). This work explores the ionic and electronic dynamic of ordered-disorder structure and offers new insights into the development of fast-charging metal ion batteries.

Structural energy storage composites based on etching engineering Fe-doped Co MOF electrode toward high energy density supercapacitors

Metal organic frameworks (MOFs) have been used widely as cathode materials for supercapacitors because of their adjustable chemical composition, variable topological structures, and relatively simple synthesis methods. However, most MOFs are insulated and their metal organic ligand coordination bonds are not stable enough in electrolytes, which greatly limits the application of MOFs in supercapacitors. The synergistic effect between transition metal doped and chemical etching is of great significance for the preparation of high-performance MOF electrodes. This study introduces Fe into Co MOF prepared by co precipitation to optimize the electronic structure of Co, and then constructed e-Fe-doped Co MOF hierarchical structure through ammonia etching. The Co MOF achieves rapid electron exchange at the electrode electrolyte interface through this synergistic effect, improving conductivity, and increasing specific surface area, exposing more active sites, effectively enhancing the electrochemical activity of the electrode. Therefore, the e-Fe-doped Co MOF-4 h has a high specific capacity of 700 C g−1 at 1 A g−1 with a 90.08 % high-rate performance. The assembled e-Fe-doped Co MOF-4 h//N-doped WC ASC provides the energy density of 80 Wh kg−1 at a power density of 800 W kg−1 with a ∼88 % capacitance retention after 10000 cycles. These results provide ideas for utilizing synergistic effects to prepare high-energy density supercapacitors using MOF materials.

Reviving Cost-Effective Organic Cathodes in Halide-Based All-Solid-State Lithium Batteries.

The evolution of inorganic solid electrolytes has revolutionized the field of sustainable organic cathode materials, particularly addressing the dissolution problems in traditional liquid electrolytes. However, current sulfide-based all-solid-state lithium-organic batteries still face challenges such as high working temperatures, high costs, and low voltage. Here, we design an all-solid-state lithium battery based on a cost-effective organic cathode material phenanthrenequinone (PQ) and a halide solid electrolyte Li2ZrCl6. Thanks to the good compatibility between PQ and Li2ZrCl6, the PQ cathode achieved a high specific capacity of 248 mAh g-1 (96% of the theoretical capacity), a high average discharge voltage of 2.74 V (vs. Li+/Li), and a good capacity retention of 95% after 100 cycles at room temperature (25 °C). Furthermore, the interaction between the high-voltage carbonyl PQ cathode and both sulfide and halide solid electrolytes, as well as the redox mechanism of PQ cathode in all-solid-state batteries, were carefully studied by a variety of advanced characterizations. We believe such a design and the corresponding investigations for the underlying chemistry give insights into the further development of practical all-solid-state lithium-organic batteries.

Reviving Cost‐Effective Organic Cathodes in Halide‐Based All‐Solid‐State Lithium Batteries

The evolution of inorganic solid electrolytes has revolutionized the field of sustainable organic cathode materials, particularly addressing the dissolution problems in traditional liquid electrolytes. However, current sulfide‐based all‐solid‐state lithium‐organic batteries still face challenges such as high working temperatures, high costs, and low voltage. Here, we design an all‐solid‐state lithium battery based on a cost‐effective organic cathode material phenanthrenequinone (PQ) and a halide solid electrolyte Li2ZrCl6. Thanks to the good compatibility between PQ and Li2ZrCl6, the PQ cathode achieved a high specific capacity of 248 mAh g‐1 (96% of the theoretical capacity), a high average discharge voltage of 2.74 V (vs. Li+/Li), and a good capacity retention of 95% after 100 cycles at room temperature (25 °C). Furthermore, the interaction between the high‐voltage carbonyl PQ cathode and both sulfide and halide solid electrolytes, as well as the redox mechanism of PQ cathode in all‐solid‐state batteries, were carefully studied by a variety of advanced characterizations. We believe such a design and the corresponding investigations for the underlying chemistry give insights into the further development of practical all‐solid‐state lithium‐organic batteries.

Nanoporous Carbon Materials Derived from Zanthoxylum Bungeanum Peel and Seed for Electrochemical Supercapacitors

In order to prepare biomass-derived carbon materials with high specific capacitance at a low activation temperature (≤700 °C), nanoporous carbon materials were prepared from zanthoxylum bungeanum peels and seeds via the pyrolysis and KOH-activation processes. The results show that the optimal activation temperatures are 700 °C and 600 °C for peels and seeds. Benefiting from the hierarchical pore structure (micropores, mesopores, and macropores), the abundant heteroatoms (N, S, and O) containing functional groups, and plentiful electrochemical active sites, the PAC-700 and SAC-600 derive the large capacities of ~211.0 and ~219.7 F g−1 at 1.0 A g−1 in 6 M KOH within the three-electrode configuration. Furthermore, the symmetrical supercapacitors display a high energy density of 22.9 and 22.4 Wh kg−1 at 7500 W kg−1 assembled with PAC-700 and SAC-600, along with exceptional capacitance retention of 99.1% and 93.4% over 10,000 cycles at 1.0 A g−1. More significantly, the contribution here will stimulate the extensive development of low-temperature activation processes and nanoporous carbon materials for electrochemical energy storage and beyond.

Mo-doping modulated cationic vacancy in Zn3V2O8 with enhanced electrochemical performance for lithium-ion batteries

Given diverse redox reactions and abundant raw materials, Zn3V2O8 with high specific capacity is considered as a potential anode material for lithium-ion batteries. Same as other transition metal oxides, Zn3V2O8 suffers from infertile conductivity, sluggish ion diffusion and fast capacity loss derived from volume expansion during discharge/charge process, further hindering its application. In this work, a novel Mo doped Zn3V2O8 (Zn3V2-xMo5x/6O8) anode material with cationic vacancy (V vacancy) has been designed through a facile sol-gel method. It is found that a small Mo-doping amount has nearly no influence on the crystal structure, morphology and element valence states of Zn3V2O8. Mo doped Zn3V2O8 samples possess smaller charge transfer resistance and higher lithium ion diffusion coefficient. The results of electrochemical performance illustrate that Mo doped Zn3V2O8 can deliver higher reversible specific capacities and better rate capability compared with Zn3V2O8, which can be ascribed to the introduction of V vacancy. In particular, when Mo-doping amount is set as 0.03, the obtained Zn3V1.97Mo0.025O8 exhibits a reversible capacity of 481.1 mAh g−1 after 600 cycles at 1 A g−1. It is believed that this work could provide an effective and feasible strategy to construct high performance transition metal vanadate anode materials for lithium-ion batteries.

Synergistic Engineering of CoO/MnO Heterostructures Integrated with Nitrogen-Doped Carbon Nanofibers for Lithium-Ion Batteries

The integration of heterostructures within electrode materials is pivotal for enhancing electron and Li-ion diffusion kinetics. In this study, we synthesized CoO/MnO heterostructures to enhance the electrochemical performance of MnO using a straightforward electrostatic spinning technique followed by a meticulously controlled carbonization process, which results in embedding heterostructured CoO/MnO nanoparticles within porous nitrogen-doped carbon nanofibers (CoO/MnO/NC). As confirmed by density functional theory calculations and experimental results, CoO/MnO heterostructures play a significant role in promoting Li+ ion and charge transfer, improving electronic conductivity, and reducing the adsorption energy. The accelerated electron and Li-ion diffusion kinetics, coupled with the porous nitrogen-doped carbon nanofiber structure, contribute to the exceptional electrochemical performance of the CoO/MnO/NC electrode. Specifically, the as-prepared CoO/MnO/NC exhibits a high reversible specific capacity of 936 mA h g−1 at 0.1 A g−1 after 200 cycles and an excellent high-rate capacity of 560 mA h g−1 at 5 A g−1, positioning it as a competitive anode material for lithium-ion batteries. This study underscores the critical role of electronic and Li-ion regulation facilitated by heterostructures, offering a promising pathway for designing transition metal oxide-based anode materials with high performances for lithium-ion batteries.

Exploring Zinc Vanadate/Cobalt Oxide (Zn3(VO4)2/CoO) Nano Hybrid Composites as Supercapacitors for Sustainable Energy Storage Applications

A hybrid nanocomposite of zinc vanadate/cobalt oxide (Zn3(VO4)2/CoO at ratios of 90/10, 80/20, 50/50, and 20/80) was obtained using a simple co-precipitation technique, then calcinated for 4 hrs at 400°C. The surface morphological, vibrational, and structural characteristics of the synthesized hybrid nanocomposites were examined. According to the structural study, orthorhombic Zn3(VO4)2 and cubic crystal systems of CoO with space groups Fm-3m were formed. The functional groups of Zinc Vanadate/Cobalt Oxide were examined using FTIR spectroscopy. A scanning electron microscopy (SEM) study reveals the nanosheets structures with the size of 200 nm. The chemical composition and formation of the Zn3(VO4)2/CoO composites were confirmed using X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the hybrid nanocomposites was assessed through CV, GCD and impedance analysis. Among the nanocomposites, Zn3(VO4)2/CoO 80/20 exhibited a high specific capacitance value of 564.36 Fg-1 and retaining 97% of their total capacitance even after 3000 cycles.

Controllable Design of Metal-Organic Framework-Derived Vanadium Oxynitride for High-Capacity and Long-Cycle Aqueous Zn-Ion Batteries.

Introducing N atoms in vanadium oxides (VOx) of aqueous Zn-ion batteries (ZIBs) can reduce their bandgap energy and enhance their electronic conductivity, thereby promoting the diffusion of Zn2+. The close-packed vanadium oxynitride (VON) generated often necessitates the intercalation of water molecules for restructuring, rendering it more conducive for zinc ion intercalation. However, its dense structure often causes structural strain and the formation of by-products during this process, resulting in decreased electrochemical performance. Herein, carbon-coated porous V2O3/VN nanosheets (p-VON@C) are constructed by annealing vanadium metal-organic framework in an ammonia-contained environment. The designed p-VON@C nanosheets are efficiently converted to low-crystalline hydrated N-doped VOx during subsequent activation while maintaining structural stability. This is because the V2O3/VN heterojunction and abundant oxygen vacancies in p-VON@C alleviate the structural strain during water molecule intercalation, and accelerate the intercalation rate. Carbon coating is beneficial to prevent p-VON@C from sliding or falling off during the activation and cycling process. Profiting from these advantages, the activated p-VON@C cathode delivers a high specific capacity of 518 mAh g-1 at 0.2 A g-1 and maintains a capacity retention rate of 80.9% after 2000 cycles at 10 A g-1. This work provides a pathway to designing high-quality aqueous ZIB cathodes.

Dendrite-Free Li5.5PS4.5Cl1.5-Based All-Solid-State Lithium Battery Enabled by Grain Boundary Electronic Insulation Strategy through In Situ Polymer Encapsulation.

Sulfide-based all-solid-state lithium batteries (ASSLBs) have attracted unprecedented attention in the past decade due to their excellent safety performance and high energy storage density. However, the sulfide solid-state electrolytes (SSEs) as the core component of ASSLBs have a certain stiffness, which inevitably leads to the formation of pores and cracks during the production process. In addition, although sulfide SSEs have high ionic conductivity, the electrolytes are unstable to lithium metal and have non-negligible electronic conductivity, which severely limits their practical applications. Herein, a grain boundary electronic insulation strategy through in situ polymer encapsulation is proposed for this purpose. A polymer layer with insulating properties is applied to the surface of the Li5.5PS4.5Cl1.5 (LPSC) electrolyte particles by simple ball milling. In this way, we can not only achieve a dense electrolyte pellet but also improve the stability of the Li metal anode and reduce the electronic conductivity of LPSC. This strategy of electronic isolation of the grain boundaries enables stable deposition/stripping of the modified electrolyte for more than 2000 h at a current density of 0.5 mA cm-1 in a symmetrical Li/Li cell. With this strategy, a full cell with Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) as the cathode shows high performance including high specific capacity, improved high-rate capability, and long-term stability. Therefore, this study presents a new strategy to achieve high-performance sulfide SSEs.

Enhanced Energy Storage Performance through Controlled Composition and Synthesis of 3D Mixed Metal-Oxide Microspheres

Binary transition metal oxide complexes (BTMOCs) in three-dimensional (3D) layered structures show great promise as electrodes for supercapacitors (SCs) due to their diverse oxidation states, which contribute to high specific capacitance. However, the synthesis of BTMOCs with 3D structures remains challenging yet crucial for their application. In this study, we present a novel approach utilizing a single-step hydrothermal technique to fabricate flower-shaped microspheres composed of a NiCo-based complex. Each microsphere consists of nanosheets with a mesoporous structure, enhancing the specific surface area to 23.66 m2 g−1 and facilitating efficient redox reactions. When employed as the working electrode for supercapacitors, the composite exhibits remarkable specific capacitance, achieving 888.8 F g−1 at 1 A g−1. Furthermore, it demonstrates notable electrochemical stability, retaining 52.08% capacitance after 10,000 cycles, and offers a high-power density of 225 W·kg−1, along with an energy density of 25 Wh·kg−1, showcasing its potential for energy storage applications. Additionally, an aqueous asymmetric supercapacitor (ASC) was assembled using NiCo microspheres-based complex and activated carbon (AC). Remarkably, the NiCo microspheres complex/AC configuration delivers a high specific capacitance of 250 F g−1 at 1 A g−1, with a high energy density of 88 Wh kg−1, for a power density of 800 W kg−1. The ASC also exhibits excellent long-term cyclability with 69% retention over 10,000 charge–discharge cycles. Furthermore, a series of two ASC devices demonstrated the capability to power commercial blue LEDs for a duration of at least 40 s. The simplicity of the synthesis process and the exceptional performance exhibited by the developed electrode materials hold considerable promise for applications in energy storage.