The 5.0, 8.0, and 10.0 wt% NiCl2-modified LiV3O8 materials are successfully prepared and the effects of NiCl2 modification on the electrochemical performance of LiV3O8 cathode have been investigated. The structural and surface morphologic properties of synthesized materials are characterized by X-ray diffraction and scanning electron microscopy. The electrochemical properties are investigated by charge–discharge testing and cyclic voltammetry. It is found that 8.0 wt% NiCl2-modified LiV3O8 shows excellent electrochemical properties. The initial discharge capacity of 8.0 wt% NiCl2-modified LiV3O8 is much higher than that of pristine LiV3O8, and can attain 336.7 mAh g−1 at the current rate of 0.5 C (300 mA g−1 is assumed to be 1 C rate). Additionally, NiCl2 modification significantly improves the cyclability of LiV3O8. The NiCl2 modification is shown to be able to suppress the capacity fade of LiV3O8 without specific capacity expense by suppressing the characteristic phase transitions during cycling.

Spherical LiNi1/3Co1/3Mn1/3O2 powders have been synthesized from co-precipitated spherical metal hydroxide. The electrochemical performances of the LiNi1/3Co1/3Mn1/3O2 electrodes in 1 M LiNO3, 5 M LiNO3, and saturated LiNO3 aqueous electrolytes have been studied using cyclic voltammetry and ac impedance tests in this work. The results show that LiNi1/3Co1/3Mn1/3O2 electrode in saturated LiNO3 electrolyte exhibits the best electrochemical performance. An aqueous rechargeable lithium battery containing LiNi1/3Co1/3Mn1/3O2 cathode, LiV2.9Ni0.050Mn0.050O8 anode, and saturated LiNO3 electrolyte is fabricated. The battery delivers an initial capacity of 98.2 mAh g−1 and keeps a capacity of 63.9 mAh g−1 after 50 cycles at a rate of 0.5 C (278 mA g−1 was assumed to be 1 C rate).

LiV3O8–Polypyrrole (LiV3O8–PPy) composite has been chemically synthesized by an oxidative polymerization of pyrrole monomer on the surface of LiV3O8 using ferric chloride as oxidizing agent. The electrochemical properties of LiV3O8–PPy composite were systematically investigated using a variety of electrochemical methods. The LiV3O8–PPy composite electrode exhibited better cycling behavior and superior rate capability as compared with the bare LiV3O8 electrode. Cyclic voltammetry corroborated the galvanostatic cycling tests, with the composite cathode material showing better reversibility than bare material. Finally, fitting the impedance results to an equivalent circuit indicated that the enhanced electrochemical performances of LiV3O8–PPy composite resulted from a facilitated kinetics of interfacial charge transfer in the presence of PPy.Research highlights► LiV3O8–PPy composite has been synthesized successfully. ► LiV3O8–PPy composite shows better cycling behavior and rate capability than LiV3O8. ► LiV3O8–PPy composite shows lower electrochemical resistance than LiV3O8.

Despite the large number of studies on the electrochemical behavior of LiV3O8 as a cathode material in nonaqueous lithium ion batteries, little information is available about the electrochemical behavior of LiV3O8 as an anode material in aqueous rechargeable lithium batteries. In this work, nanostructured LiV3O8 is successfully prepared using a low-temperature solid-state method. The electrochemical properties of the LiV3O8 electrode in 1 M, 5 M, and saturated LiNO3 aqueous electrolytes have been characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge experiments. The results show that LiV3O8 electrode in saturated LiNO3 electrolyte exhibits good electrochemical performance in terms of specific capacity and electrochemical cycling performance. LiV3O8 electrode can be reversibly cycled in saturated LiNO3 aqueous electrolyte for 300 cycles at a rate of 0.5 C (300 mA g−1 is assumed to be 1 C rate) with impressive specific capacities.Highlights► Nanostructured LiV3O8 has been prepared successfully. ► LiV3O8 shows good electrochemical performance in saturated LiNO3 electrolyte. ► Electrochemical performance of LiV3O8 as anode material in ARLBs has been studied.

The nanostructural multiphase nickel hydroxide, which was with doped at least three modifier elements has been synthesized. Scanning electron microscope (SEM) micrograph showed that the nanostructural multiphase nickel hydroxide was consisted of nanostructural particles. It has been confirmed by X-ray diffraction (XRD) examination that the compound has a mixed structure of α-Ni(OH)2 and β-Ni(OH)2. The tap-density of the nanostructural multiphase nickel hydroxide is 1.7–1.9 g/cm3 and the discharge capacity can reach 375 mAh/g. The electrochemical studies revealed that the compound has much better redox reversibility, a much lower oxidation potential of Ni(II) than the corresponding oxidation state compared with β-Ni(OH)2, and a much higher reduction potential. Since it has much higher tap-density and better electrochemical performance than Al-stabilized α-Ni(OH)2 and usual β-Ni(OH)2, it may be a promising positive active material for alkaline rechargeable batteries.