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Aqueous zinc‐ion batteries have drawn increasing attention due to the intrinsic safety, cost‐effectiveness and high energy density. However, parasitic reactions and non‐uniform dendrite growth on the Zn anode side impede their application. Herein, a multifunctional additive, ammonium dihydrogen phosphate (NHP), is introduced to regulate uniform zinc deposition and to suppress side reactions. The results show that the NH4+ tends to be preferably absorbed on the Zn surface to form a "shielding effect" and blocks the direct contact of water with Zn. Moreover, NH4+ and (H2PO4)− jointly maintain pH values of the electrode‐electrolyte interface. Consequently, the NHP additive enables highly reversible Zn plating/stripping behaviors in Zn//Zn and Zn//Cu cells. Furthermore, the electrochemical performances of Zn//MnO2 full cells and Zn//active carbon (AC) capacitors are improved. This work provides an efficient and general strategy for modifying Zn plating/stripping behaviors and suppressing side reactions in mild aqueous electrolyte. [ABSTRACT FROM AUTHOR]

To promote the commercial application of sodium ion batteries (SIBs), new high‐stability and high‐capacity anode materials are needed. Metal oxides show great promise, but significant issues relating to their low electrical conductivity and unstable structure during charge storage must be resolved. Herein, a new composite anode consisting of pseudohexagonal Nb2O5 (TT‐Nb2O5) nanoparticles strongly anchored to carbon nanotubes (CNT) through a glucose‐derived carbon framework (Nb2O5/g‐CNT) was synthesised and assessed for use as the anode in SIBs. This represents the first application of TT‐Nb2O5 in SIBs. The composite is shown to offer high specific capacity (203 mAh g−1 at 0.2 A g−1), good rate capability (53 mAh g−1 at high current density of 5 A g−1), and a high‐capacity retention rate (135 mAh g−1 at 0.2 A g−1 between 25 and 300 cycles). This is attributed to high electrical conductivity and flexibility offered by the designed carbon framework, the superior capacity of the TT‐Nb2O5 and the linkage between the two provided by the bonding glucose derived carbon. This work therefore demonstrates a scalable route for the application of metal oxides in future high‐performance SIB systems. [ABSTRACT FROM AUTHOR]

Herein, we present a freestanding and flexible 3D nanocomposite made of polyhedral spherical FeCoS2 and nitrogen-doped hollow carbon nanofibers (FeCoS2@N-HCNFs) that is synthesized through coaxial electrospinning, high-temperature calcination, and a facile solvothermal process. As a binder-free anode composite for potassium-ion batteries (PIBs), FeCoS2@N-HCNF presents a high specific discharge capacity on the first lap (701.2 mA h g−1 at 100 mA g−1) and superior cycling stability (132.6 mA h g−1 at 3200 mA g−1 after 600 cycles). The impressive electrochemical performance can be ascribed to the unique 3D structure, such as the enormous specific surface area of the mesoporous structure beneficial for K+ transfer, the three-dimensional hollow carbon nanofiber scaffold enhances the structural stability, and polyhedral spherical FeCoS2 improves the overall specific capacity. According to the above description, the FeCoS2@N-HCNF anode is a promising candidate for advanced potassium-ion batteries. [ABSTRACT FROM AUTHOR]