Shibing Ni

Fabrication of a porous NiS/Ni nanostructured electrodevia a dry thermal sulfuration method and its application in a lithium ion battery

A novel dry thermal sulfuration approach has been used to fabricate a porous NiS/Ni nanostructured cathode electrode. Galvanostatic battery testing shows that the NiS/Ni electrode exhibits high discharge/charge capacity and excellent cycle performance. The performances are due to its favorable porous structure and the fine electrical contact between NiS and Ni.

The investigation of Ni(OH)2/Ni as anodes for high performance Li-ion batteries

Ni(OH)2 nanowalls were prepared via a novel hydrothermal method, which show excellent cycling stability as anodes for Li-ion batteries. The initial discharge and charge capacities are 0.63 and 0.49 mA h cm−2, respectively, showing no evident capacity attenuation over 100 cycles.

Reduced graphene oxide modified Li2FeSiO4/C composite with enhanced electrochemical performance as cathode material for lithium ion batteries.

Reduced graphene oxide modified Li2FeSiO4/C (LFS/(C+rGO)) composite is successfully synthesized by a citric-acid-based sol-gel method and evaluated as cathode material for lithium ion batteries. The LFS/(C+rGO) shows an improved electronic conductivity due to the conductive network formed by reduced graphene oxide nanosheets and amorphous carbon in particles. Electrochemical impedance spectroscopy results indicate an increased diffusion coefficient of lithium ions (2.4 × 10(-11) cm(2) s(-1)) for LFS/(C+rGO) electrode. Compared with LFS with only amorphous carbon, the LFS/(C+rGO) electrode exhibits higher capacity and better cycling stability. It delivers a reversible capacity of 178 mAh g(-1) with a capacity retention ratio of 94.5% after 40 cycles at 0.1 C, and an average capacity of 119 mAh g(-1) at 2 C. The improved performance can be contributed to the reduced crystal size, good particle dispersion, and the improved conductive network between LFS particles.

The fine electrochemical performance of porous Cu3P/Cu and the high energy density of Cu3P as anode for Li-ion batteries

Porous Cu3P/Cu anode was prepared, which shows good electrochemical performance because of a novel electrochemical reconstruction in cycling. The compatible voltage plateau, specific capacity and density of Cu3P suggest that it can be an ideal high energy density anode for Li-ion batteries.

Systematic investigation on Cadmium-incorporation in Li2FeSiO4/C cathode material for lithium-ion batteries

Cadmium-incorporated Li2FeSiO4/C composites have been successfully synthesized by a solid-state reaction assisted with refluxing. The effect and mechanism of Cd-modification on the electrochemical performance of Li2FeSiO4/C were investigated in detail by X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, Raman spectra, transmission electron microscopy, positron annihilation lifetime spectroscopy and Doppler broadening spectrum, and electrochemical measurements. The results show that Cd not only exists in an amorphous state of CdO on the surface of LFS particles, but also enters into the crystal lattice of LFS. Positron annihilation lifetime spectroscopy and Doppler broadening spectrum analyses verify that Cd-incorporation increases the defect concentration and the electronic conductivity of LFS, thus improve the Li+-ion diffusion process. Furthermore, our electrochemical measurements verify that an appropriate amount of Cd-incorporation can achieve a satisfied electrochemical performance for LFS/C cathode material.

Superior electrochemical performance of Li3VO4/N-doped C as an anode for Li-ion batteries

A high performance Li3VO4/N-doped C anode was successfully prepared, which delivers an initial discharge/charge capacity of 600/472 mA h g−1 at 150 mA g−1, maintaining 462/460 mA h g−1 after 100 cycles. It shows no capacity attenuation over 2200 cycles at 2000 mA g−1, delivering a discharge/charge capacity of 267/264 mA h g−1.

The preparation of NiV3O8/Ni composite via an in situ corrosion method and its use as a new sort of anode material for Li-ion batteries

A NiV3O8/Ni composite was successfully prepared via a novel in situ corrosion method, which shows good electrochemical performance as a new sort of anode for Li-ion batteries. After 60 cycles at various rates from 0.1 to 20 C, the discharge capacity can be restored when the charge–discharge rate is lowered to 0.1 C.

Prominent electrochemical performance of a Li3VO4/C–Ni anode via hierarchically porous architecture design

Prominent electrochemical performance of a Li3VO4/C–Ni electrode is achieved via hierarchically porous architecture design. The discharge/charge capacities can be maintained at 578/575 mA h g−1 after 190 cycles at various rates. After 2000 cycles at a high current rate of 10C, the discharge/charge capacities can both be maintained at 325 mA h g−1.

Synthesis and electrochemical performance of Na-modified Li2Fe0.5Mn0.5SiO4 cathode material for Li-ion batteries

A series of Li2−xNaxFe0.5Mn0.5SiO4/C (x = 0.00, 0.01, 0.03 and 0.05) composites have been synthesized via a refluxing-assisted solid-state reaction, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), galvanostatic charge–discharge measurements, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests. XRD results show that Li2−xNaxFe0.5Mn0.5SiO4/C can be well indexed as the structure of two mixed polymorphs with space group P21 and Pmn21. XPS results confirms that Na not only exists on the surface of Li2Fe0.5Mn0.5SiO4 particles, but also has been successfully doped into the crystal lattice of Li2Fe0.5Mn0.5SiO4. Na-doping can significantly improve the discharge capacity and the rate capability of Li2Fe0.5Mn0.5SiO4/C. The enhanced electrochemical performance can be attributed to the increased electronic conductivity, the decreased charge transfer impedance, and the improved Li-ion diffusion coefficient.

Synthesis and electrochemical performance of Li2FeSiO4/C cathode material using ascorbic acid as an additive

Carbon-coated Li2FeSiO4 composite (LFS/C-AA) was synthesized via a refluxing-assisted solid-state reaction by using ascorbic acid as additive and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, galvanostatic charge/discharge measurements, and electrochemical impedance spectra (EIS) tests. The results show that ascorbic acid can to some extent prohibit the oxidation of Fe2+ during the synthesis process, and the pyrolytic carbon from ascorbic acid shows higher electronic conductivity and improves the degree of graphitization of residual carbon in the LFS/C-AA composite. Compared with LFS/C prepared without ascorbic acid, LFS/C-AA displays better electrochemical performance. The desirable property is attributed to the reduced particle size, the enhanced electronic conductivity, and the improved diffusion coefficient of lithium ions.