Hangzhou, China
Hangzhou, China

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Zhang J.,Zhejiang Normal University | Xiang J.,Narada Power Source Co. | Dong Z.,Zhejiang Normal University | Liu Y.,Zhejiang Normal University | And 3 more authors.
Electrochimica Acta | Year: 2014

We report herein a three-dimensional structured carbon material as the cathode supporter for rechargeable lithium - sulfur batteries. Highly porous activated carbon foam (ACF) with micromesoporosity has been synthesized through carbonizing pomelo peel and activating by KOH. Elemental sulfur has been loaded to the micropores through a solution infiltration method to form a S/ACF nanocomposite. The resulted S/ACF nanocomposite with 60% sulfur has been tested as novel cathodes for Li - S batteries. The S/ACF nanocomposite showed an initial discharge capacity of 1258 mAh g-1 at 0.2 C rate. After 100 cycles of charge/discharge, the S/ACF nanocomposite retained a high specific capacity of 750 mAh g-1 with a Coulombic efficiency of 96%. The material delivered a capacity of more than 700 mAh g-1 at 2C rate and can be recovered to 880 mAh g-1 when the rate is returned to 0.2C. The results show that the ACF with 3D connected structure could be a promising binder-free cathode supporter for rechargeable Li - S battery with high specific energy. © 2013 Elsevier Ltd. All rights reserved.

Xiang J.,Narada Power Source Co. | Li G.,Architectural Design and Research Institute of Zhejiang Province
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2013

Bud-like FeS2 powder was synthesized by a solvothermal method with the help of polyvinylpyrrolidone (PVP). The bud-like FeS2 microshperes with the diameters of 2.0-3.0 μm were consisted of the submicro-flakes with 0.5-1μm in width and length, and about 60 nm in thickness. As an anode material for Li-ion batteries, the bud-like FeS 2 delivered initial specific discharge capacity of 773 and 749 mAh g-1, and could sustain 387 and 368 mAh g-1 after 30 cycles at current densities of 45 and 89 mA g-1, respectively, much higher than the solid one obtained without PVP. The bud-like FeS2 microshperes also showed large diffusion coefficient of Li-ions ( DLi+) calculated by Galvanostatic intermittent titration (GITT). The improved electrochemical performance of bud-like FeS2 was due to the unique structure which provides large contact area between the FeS2 microspheres and electrolyte, decreased polarization and large DLi+, leading to enhanced electrode reaction kinetics. © 2013 Elsevier B.V.

Song S.G.,Zhejiang University of Technology | Li X.P.,Narada Power Source Co. | Margaris D.P.,Georgian Technical University
Journal of Mechanical Engineering Research and Developments | Year: 2016

Single energy electric vehicle was set as the study object. Feedback current range was determined by analyzing electric vehicle regenerative braking principle. The mathematical models of battery maximum charging current was established based on hybrid pulse power characterization method. Considering the reasonable distribution of regenerative braking and hydraulic braking, with the braking current as the control object, electric-hydraulic regenerative braking strategy based on variable current feedback was proposed, and simulation of the control model was carried out. The result show that this regenerative braking strategy improves the recovery efficiency of braking energy under the premise of ensuring battery charging safety.

Song S.G.,Zhejiang University of Technology | Li X.P.,Narada Power Source Co.
Environment, Energy and Applied Technology - Proceedings of the 2014 3rd International Conference on Frontier of Energy and Environment Engineering, ICFEEE 2014 | Year: 2015

In order to solve the problem of energy efficiency during electric vehicles regenerative braking, according to regenerative braking energy and energy flow process, the key factors affecting the regenerative braking was analyzed. The regenerative braking efficiency evaluation index was proposed considering braking control, mechanical transmission, motor and battery combined efficiency. Analysis of the motor braking torque, speed and battery SOC for energy recovery efficiency test, based on experiment data to fit curve of motor and battery combined efficiency, and established energy recovery efficiency model. With conventional braking were simulated, obtained the regenerative braking efficiency under different working conditions, and verified regenerative braking efficiency model. © 2015 Taylor & Francis Group, London.

Song S.G.,Narada Power Source Co. | Song S.G.,Zhejiang University of Technology | Song S.G.,Tongji University | Li X.P.,Narada Power Source Co. | Sun Z.C.,Tongji University
Advanced Materials Research | Year: 2014

In order to evaluate the lithium-ion battery charging during electric vehicles regenerative braking, by testing on different initial SOC, charging current and temperature, the charging curves of lithium-ion battery are drawn under different conditions, and various parameters are derived. Based on a single factor in the impact of change on energy recovery, analyzed the influencing factors of coupling mechanism. Get approximation functions between energy recovery and multi-factor using multiple regression analysis method, and built energy recovery models. According to some experimentation with measured value and the calculated value, indicated the set of polynomials energy recovery model efficiency. © (2014) Trans Tech Publications, Switzerland.

Lu Y.,Zhejiang University | Wang X.,Zhejiang University | Mai Y.,Zhejiang University | Xiang J.,Narada Power Source Co. | And 5 more authors.
Journal of Physical Chemistry C | Year: 2012

Hybridizing Ni 2P/graphene sheet composite is successfully accomplished via a one-pot solvothermal method. As anode materials for lithium-ion batteries, the Ni 2P spheres with sizes of 10-30 nm can effectively prevent the agglomeration of graphene sheets. In turn, the graphene sheets with good electrical conductivity serve as a conducting network for fast electron transfer between the active materials and charge collector, as well as buffered spaces to accommodate the volume expansion/contraction during cycling. The cyclic stability and rate capability of Ni 2P are significantly improved after the incorporation of graphene sheets. After 50 cycles, the Ni 2P/graphene sheet hybrid delivers a capacity of 450 mA h g -1 and 360 mA h g -1 at a current density of 54.2 and 542 mA g -1, respectively. The voltage hysteresis of Ni 2P with and without graphene sheets is also discussed. The incorporation of graphene sheets can partly decrease the voltage polarization, and modify the thickness of solid electrolyte interface (SEI) film. © 2012 American Chemical Society.

Lu Y.,Zhejiang University | Tu J.P.,Zhejiang University | Xiang J.Y.,Narada Power Source Co. | Wang X.L.,Zhejiang University | And 3 more authors.
Journal of Physical Chemistry C | Year: 2011

Hierarchical, nanostructured nickel phosphide (h-Ni2P) spheres are synthesized by a one-pot reaction from an organic-phase mixture of nickel acetylacetonate, trioctylphosphine, tri-n-octylamine, and oleylamine (OAm). OAm is used as a surfactant to modify the surface morphology of Ni2P spheres. The h-Ni2P spheres are composed of ordered nanoparticles with 5-10 nm sizes and filled by amorphous carbon. The hierarchical structure can greatly increase the contact area between Ni2P and electrolyte, which provides more sites for Li+ accommodation, shortens the diffusion length of Li+, and enhances the reactivity of the electrode reaction. Also, the amorphous carbon and the hierarchical Ni2P nanostructures can buffer volume expansion and thus increase the electrode stability during cycling. In the context of storage behavior, the h-Ni 2P electrode exhibits high capacity as well as Coulombic efficiency. After 50 cycles, the reversible capacity of h-Ni2P spheres is 365.3 mA h g-1 at 0.5 C and 257.8 mA h g-1 at 1 C, much higher than that of Ni2P spheres (97.2 mA h g-1 at 0.5 C). At a high rate of 3 C, the specific capacity of h-Ni2P is still as high as 167.1 mA h g-1. © 2011 American Chemical Society.

Lu Y.,Zhejiang University | Tu J.-P.,Zhejiang University | Xiong Q.-Q.,Zhejiang University | Xiang J.-Y.,Narada Power Source Co. | And 6 more authors.
Advanced Functional Materials | Year: 2012

A monophase nickel phosphide/carbon (Ni 5P 4/C) composite with a thin carbon shell is controllably synthesized via the two-step strategy of a wet-chemistry reaction and a solid-state reaction. In this fabrication, the further diffusion of phosphorus atoms in the carbon shell during the solid-state reaction can be responsible for a chemical transformation from a binary phase of Ni 5P 4-Ni 2P to monophase Ni 5P 4. Galvanostatic charge-discharge measurements indicate that the Ni 5P 4/C composite exhibits a superior, high rate capacibility and good cycling stability. About 76.6% of the second capacity (644.1 mA h g -1) can be retained after 50 cycles at a 0.1 C rate. At a high rate of 3 C, the specific capacity of Ni 5P 4/C is still as high as 357.1 mA h g -1. Importantly, the amorphous carbon shell can enhance the conductivity of the composite and suppress the aggregation of the active particles, leading to their structure stability and reversibility during cycling. As is confirmed from X-ray-diffraction analysis, no evident microstructural changes occur upon cycling. These results reveal that highly crystalline Ni 5P 4/C is one of the most promising anode materials for lithium-ion batteries. © 2012 WILEY-VCH Verlag erlag GmbH & Co. KGaA, Weinheim.

Zhong G.,China Electric Power Research Institute | Su W.,China Electric Power Research Institute | Chen D.,Narada Power Source Co. | Xiang J.,Narada Power Source Co. | And 2 more authors.
MATEC Web of Conferences | Year: 2015

Negative strap corrosion is an important reason for the failure of valve regulated lead acid battery. This paper selected the Pb-Sb alloy material and Pb-Sn alloy material, made an investigation on the negative corrosion resistance and hydrogen evolution of these two alloy materials by scanning electron microscope analysis, metallographic analysis, chemical study and linear sweep voltammetry, and discussed the influence of lead alloy hydrogen evolution on the negative strap corrosion. The results showed that the hydrogen evolution reaction rates of the alloys had an impact on the corrosion areas with the maximum thickness of the alloys and the depth of corrosion layers. Greater hydrogen evolution reaction rate can lead to shorter distance between the corrosion area with the maximum thickness and the liquid level; whereas the greater corrosion layer thickness can bring aggravated risk of negative strap corrosion failure. © Owned by the authors, published by EDP Sciences, 2015.

Zhang D.,Zhejiang University | Mai Y.J.,Zhejiang University | Xiang J.Y.,Narada Power Source Co. | Xia X.H.,Zhejiang University | And 2 more authors.
Journal of Power Sources | Year: 2012

Carbon coated FeS 2 (FeS 2/C) composite is prepared via a simple solid state reaction using glucose as carbon source. The porous FeS 2 particles are uniformly surrounded by the amorphous carbon coating. As an anode material for lithium ion batteries, the FeS 2/C composite exhibits higher reversible capacity and better cycling performance than the unmodified FeS 2. The specific capacity of the FeS 2/C composite after 50 cycles is 495 mAh g -1, much higher than that of FeS 2 (345 mAh g -1). In order to investigate the effect of carbon coating, the cycled electrodes have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The improvement is attributed to the introduction of carbon coating, which can enhance the conductivity, reduce the dissolution of sulfur and corrosion from HF, and stabilize the porous structure during cycling. © 2012 Elsevier B.V. All rights reserved.

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