Conversion of MoS₂ to a Ternary MoS_2–<i>x</i>Se_<i>x</i> Alloy for High-Performance Sodium-Ion Batteries

MoS2 has attracted tremendous attention as an anode for Na-ion batteries (NIBs) owing to its high specific capacity and layered graphite-like structure. Herein, MoS2 is converted to a ternary MoS2–xSex alloy through the selenizing process in order to boost the electrochemical performance for Na-ion batteries. Conversion of MoS2 to MoS2–xSex expands interlayer spacing, improves electronic conductivity, and creates more defects. The expanded interlayer spacing decreases Na+ diffusion resistance and facilitates Na+ fast transfer. The integrated graphene as a conductive network offers effective pathway for electron migration and maintains structural stability of electrodes during cycles. The ternary MoS1.2Se0.8/graphene (MoS1.2Se0.8/G) electrode demonstrates an extremely high reversible capacity of 509 mA h g–1 after 200 cycles at 0.1 A g–1 (capacity retention of 109%) as an anode for sodium-ion batteries. Even at 2 A g–1 and after 700 cycles, the MoS1.2Se0.8/G electrode also displays a relatively high reversible capacity of 178 mA h g–1. Full cells assembled with Na3V2(PO4)2F3 cathodes and MoS1.2Se0.8/G anodes reveal high charge/discharge capacities. This work demonstrates that the ternary MoS2–xSex alloy could be a potential anode material for Na-ion storage

VN Quantum Dots Embedded in N‑Doped Carbon for High-Performance Lithium Storage

Vanadium nitride (VN) with a high theoretical specific capacity and electronical conductivity is a potential material for lithium-ion batteries (LIBs). Regrettably, the large volume changes and slow Li+ diffusion kinetics lead to a rapid attenuation of capacity and poor rate capability. Therefore, a vanadium nitride/N-doped carbon (VN/NC) nanocomposite has been prepared through a simple and one-step method. The N-doped carbon framework is evenly inserted with vanadium nitride (VN) quantum dots. The VN/NC nanocomposite can provide up to 755 mAh g–1 of special capacity after 200 cycles at 0.1 A g–1 and 396 mAh g–1 after 1000 cycles at 1.0 A g–1 in LIBs. Based on a LiNi0.33Co0.33Mn0.33O2 (NCM) cathode and a VN/NC anode, the full cell also exhibits a desirable capacity of 320 mAh g–1 after 350 cycles at 1.0 A g–1. The reason for such good electrochemical properties is that VN quantum dots provide high capacity and N-doped carbon acts as a conductive network and mechanical support

Simultaneously Tailoring Zinc Deposition and Solvation Structure by Electrolyte Additive

Aqueous zinc ion batteries (AZIBs) have attracted intense attention due to their high safety and low cost. Unfortunately, the serious dendrite growth and side reactions of the Zn metal anode in an aqueous electrolyte result in rapid battery failure, hindering the practical application of AZIBs. Herein, sodium gluconate as a dual-functional electrolyte additive has been employed to enhance the electrochemical performance of AZIBs. Gluconate anions preferentially adsorb on the surface of the Zn anode, which effectively prevents H2 evolution and induces uniform Zn deposition to suppress dendrite growth. Moreover, the gluconate anions can highly coordinate with Zn2+, promoting the dissolution of [Zn(H2O)6]2+ to inhibit side reactions and the water-induced corrosion reaction. As a result, the Zn||Zn symmetric battery exhibits a long-term cycling stability of over 3000 h at 1 mA cm–2/1 mA h cm–2 and 600 h at 10 mA cm–2/10 mA h cm–2. Furthermore, the NH4V4O10||Zn full battery also displays excellent cycling stability and a high reversible capacity of 193 mA h g–1 at 2 A g–1 after 1000 cycles. Given the low-cost advantage of SG, the proposed interface chemistry modulation strategy holds considerable potential for promoting the commercialization of AZIBs

Constructing Highly Stable Zinc Metal Anodes via Induced Zn(002) Growth

The nonuniform electric field at the surface of a zinc (Zn) anode, coupled with water-induced parasitic reactions, exacerbates the growth of Zn dendrites, presenting a significant impediment to large-scale energy storage in aqueous Zn-ion batteries. One of the most convenient strategies for mitigating dendrite-related issues involves controlling crystal growth through electrolyte additives. Herein, we present thiamine hydrochloride (THC) as an electrolyte additive capable of effectively stabilizing the preferential deposition of the Zn(002) plane. First-principles calculations reveal that THC tends to adsorb on Zn(100) and Zn(101) planes and is capable of inducing the deposition of Zn ion onto the (002) plane and the preferential growth of the (002) plane, resulting in a flat and compact deposition layer. A THC additive not only effectively suppresses dendrite growth but also prevents the generation of side reactions and hydrogen evolution reaction. Consequently, the Zn||Zn symmetric battery exhibits long-term cycling stability of over 3000 h at 1 mA cm–2/1 mAh cm–2 and 1000 h at 10 mA cm–2/10 mAh cm–2. Furthermore, the NH4V4O10||Zn full battery also displays excellent cycling stability and a high reversible capacity of 210 mAh g–1 after 1000 cycles at 1 A g–1, highlighting a significant potential for practical applications

Additional file 1 of Changes in expression levels of erythrocyte and immune-related genes are associated with high altitude polycythemia

Supplementary Material

Additional file 3 of Changes in expression levels of erythrocyte and immune-related genes are associated with high altitude polycythemia

Supplementary Material

Highly Reversible Zn Metal Anode with Low Voltage Hysteresis Enabled by Tannic Acid Chemistry

The zinc dendrites and side reactions formed on the zinc anode have greatly hindered the development of aqueous zinc-ion batteries (ZIBs). Herein, we introduce tannic acid (TA) as an additive in the ZnSO4 (ZSO) electrolyte to enhance the reversible Zn plating/stripping behavior. TA molecules are found to adsorb onto the zinc surface, forming a passivation layer and replacing some of the H2O molecules in the Zn2+ solvation sheath to form the [Zn(H2O)6–xTAx]2+ complex; this process effectively prevents side reactions. Moreover, the lower desolvation energy barrier of the [Zn(H2O)6–xTAx]2+ structure facilitates uniform Zn metal deposition and enables a stable plating/stripping lifespan of 2500 h with low voltage hysteresis (53 mV at 0.5 mA cm–2) as compared to the ZSO electrolyte (167 h and 104 mV). Additionally, the incorporation of the MnO2 cathode in the TA + ZSO electrolyte shows improved cycling capacity retention, from 64% (ZSO) to 85% (TA + ZSO), after 250 cycles at 1 A g–1, demonstrating the effectiveness of the TA additive in enhancing the performance of ZIBs

Additional file 2 of Changes in expression levels of erythrocyte and immune-related genes are associated with high altitude polycythemia

Supplementary Material