MnS hollow microspheres combined with carbon nanotubes for enhanced performance sodium-ion battery anode

Sulfur-bridged bonds enabled structure modulation and space confinement of MnS for superior sodium-ion capacitors

Manganese sulfide (MnS) is a promising converion-type anode for sodium storage, owing to the virtues of high theoretical capacity, coupled with it crustal abundance and cost-effectiveness. Nevertheless, MnS suffers from inadequate electronic conductivity, sluggish Na+ reaction kinetics and considerable volume variation during discharge/charge process, thereby impeding its rate capability and capacity retention. Herein, a novel lamellar heterostructured composite of Fe-doped MnS nanoparticles/positively charged reduced graphene oxide (Fe-MnS/PG) was synthesized to overcome these issues. The Fe-doping can accelerate the ion/electron transfer, endowing fast electrochemical kinetics of MnS. Meanwhile, the graphene space confinement with strong MnSC bond interactions can facilite the interfacial electron transfer, hamper volume expansion and aggregation of MnS nanoparticles, stabilizing the structural integrity, thus improving the Na+ storage reversibility and cyclic stability. Combining the synergistic effect of Fe-doping and space confinement with strong MnSC bond interactions, the as-produced Fe-MnS/PG anode presents a remarkable capacity of 567 mAh/g at 0.1 A/g and outstanding rate performance (192 mAh/g at 10 A/g). Meanwhile, the as-assembled sodium-ion capacitor (SIC) can yield a high energy density of 119 Wh kg-1 and a maximum power density of 17500 W kg-1, with capacity retention of 77 % at 1 A/g after 5000 cycles. This work offers a promising strategy to develop MnS-based practical SICs with high energy and long lifespan, and paves the way for fabricating advanced anode materials.

A quasi-3D Sb2S3/reduced graphene oxide/MXene (Ti3C2Tx) hybrid for high-rate and durable sodium-ion batteries

Antimony sulfide (Sb₂S₃) is a promising anode material for sodium-ion batteries (SIBs) owing to its high theoretical capacity and superior reversibility. However, its cycling life and rate performance are seriously impeded by the inferior inherent electroconductibility and tremendous volume change in the charging/discharging processes. Herein, a quasi three-dimensional (3D) Sb₂S₃/RGO/MXene composite, with Sb₂S₃ nanoparticles (∼15 nm) uniformly distributed in the quasi-3D RGO/MXene architecture, was prepared by a toilless hydrothermal treatment. The RGO/MXene conductive substrate not only alleviates the volume expansion of Sb₂S₃, but also promotes electrolyte infiltration and affords highways for ion/electron transport. More importantly, the synergistic effects between RGO and Ti₃C₂T_x MXene are extremely favourable to maintain the integrity of the electrode during cycling. As a result, the Sb₂S₃/RGO/MXene composite exhibits a high reversible capacity of 633 mA h g^-1 at 0.2 A g^-1, outstanding rate capability (510.1 mA h g^-1 at 4 A g^-1) and good cycling performance with a capacity loss of 16% after 500 cycles.

Electrochemical reaction behavior of MnS in aqueous zinc ion battery

Rechargeable aqueous zinc ion battery (ZIB) is reviving as a promising energy storage device with respect to its distinguished safeness, cost-effectiveness, and eco-friendliness. However, its practical application is still challenged...

High-rate transition metal-based cathode materials for battery-supercapacitor hybrid devices

With the rapid development of portable electronic devices, electric vehicles and large-scale grid energy storage devices, there is a need to enhance the specific energy density and specific power density of related electrochemical devices to meet the fast-growing requirements of energy storage. Battery-supercapacitor hybrid devices (BSHDs), combining the high-energy-density feature of batteries and the high-power-density properties of supercapacitors, have attracted mass attention in terms of energy storage. However, the electrochemical performances of cathode materials for BSHDs are severely limited by poor electrical conductivity and ion transport kinetics. As the rich redox reactions induced by transition metal compounds are able to offer high specific capacity, they are an ideal choice of cathode materials. Therefore, this paper reviews the currently advanced progress of transition metal compound-based cathodes with high-rate performance in BSHDs. We discuss some efficient strategies of enhancing the rate performance of transition metal compounds, including developing intrinsic electrode materials with high conductivity and fast ion transport; modifying materials, such as inserting defects and doping; building composite structures and 3D nano-array structures; interfacial engineering and catalytic effects. Finally, some suggestions are proposed for the potential development of cathodes for BSHDs, which may provide a reference for significant progress in the future.

Rock-Salt MnS0.5Se0.5 Nanocubes Assembled on N-Doped Graphene Forming van der Waals Heterostructured Hybrids as High-Performance Anode for Lithium- and Sodium-Ion Batteries

Manganese-based chalcogenides would be of latent capacity in serving as anodes for assembling lithium- and/or sodium-ion batteries (LIBs/SIBs) due to their large theoretical capacity, low price, and low-toxicity functionality, while the low electroconductivity and easy agglomeration behavior may impede their technical applications. Here, a solid-state solution of MnS_0.5Se_0.5 nanocubes in rock-salt phase has been synthesized for the first time at a relatively low temperature from the precursors of Mn(II) acetylacetonate with dibenzyl dichalcogens in oleylamine with octadecene, and the MnS_0.5Se_0.5 nanocubes have been assembled with N-doped graphene to form a new kind of heterostructured nanohybrids (shortened as MnS_0.5Se_0.5/N-G hybrids), which are very potential for the fabrication of metal-ion batteries including LIBs and/or SIBs. Investigations revealed that there have been dense vacancies generated and active sites increased via nonequilibrium alloying of MnS and MnSe into the solid-solution MnS_0.5Se_0.5 nanocubes with segregation and defects achieved in the low-temperature solution synthetic route. Meanwhile, the introduction of N-doped graphene forming heterojunction interfaces between MnS_0.5Se_0.5 and N-doped graphene would efficiently enhance their electroconductivity and avoid agglomeration of the active MnS_0.5Se_0.5 nanocubes with considerably improved electrochemical properties. As a result, the MnS_0.5Se_0.5/N-G hybrids delivered superior Li/Na storage capacities with outstanding rate performance as well as satisfactorily lasting stability (1039/457 mA h g^-1 at 0.1 A g^-1 for LIBs/SIBs). Additionally, full-cell LIBs of the anodic MnS_0.5Se_0.5/N-G constructed with cathodic LiFePO₄ (LFP) further confirmed the promising future for their practical application.

Improved sodium storage properties of nickel sulfide nanoparticles decorated on reduced graphene oxide nanosheets as an advanced anode material

For sodium ion batteries, the fabrication of nanocrystal anode materials has been identified as a satisfactory strategy to improve electrochemical performance and maintain the structural integrity of electrodes. However, the issues of agglomeration and serious volume variation have always existed within the process of charging/discharging in anode materials. In this work, a series of composites of nickel sulfide nanoparticles decorated on reduced graphene oxide nanosheets (denoted as NiS₂@rGO) were successfully synthesized via a simple one-step hydrothermal method under different temperatures. The strategy of confining nickel sulfide nanoparticles within the interlayer of graphene nanosheets can not only avoid the agglomeration, but also alleviate the volume change to some extent in electrode materials. For sodium ion storage, the NiS₂@rGO synthesized at 160 °C exhibited a higher reversible capacity and better rate capability.