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Shenzhen, China

Zhang H.,South China University of Technology | Hu R.,South China University of Technology | Liu H.,South China University of Technology | Sun W.,South China University of Technology | And 5 more authors.
Journal of Materials Chemistry A | Year: 2016

In order to further enhance the reversible capacity and cyclability for lithium storage of Sn-based alloy anode materials, a spherical-shaped Sn-Fe3O4@C ternary-phase composite consisting of nanosized tin (Sn), magnetite (Fe3O4), and graphite (C) was prepared via a two-step process using high-efficiency discharge plasma-assisted milling (P-milling). Ultrafine Sn nanoparticles were embedded and tightly contacted with nanosized Fe3O4, with graphite nanosheets coating the outside to form a multiscale spherical structure. The Sn-Fe3O4@C nanocomposite anodes demonstrate a stable and high capacity of 793 mA h g-1 after 240 cycles between 0.01 and 3.0 V vs. Li/Li+ at 200 mA g-1. Furthermore, a reversible capacity of ∼750 mA h g-1 was obtained after 500 cycles, even when the current density increased to 2000 mA g-1. The high capacity, good cycle performance, and superior high-rate capability characteristics were attributed to the unique nanostructure of the Sn-Fe3O4@C composites. The good dispersion of co-existing Sn and Fe3O4 nanoballs in a spherical carbon matrix resulted in an electrode with high structural stability and fast kinetics for Li ion and electron transfer, which contributed to high reversibility of alloying reactions in Sn and conversion reactions of Fe3O4. Furthermore, the spherical shape of the materials and simple preparation as compared to those of commercial anodes make the Sn-Fe3O4@C composites good candidates for practical applications. © The Royal Society of Chemistry 2016. Source

Sunwoda Electronic Co. | Date: 2013-09-03

Computers; computer peripheral devices; recorded computer software, namely, computer software for use in database management; electronic pocket translators; time clocks, namely, time recording devices; electronic notice boards; mechanical signs; antennas; telephone apparatus; video telephones; navigation apparatus for vehicles in the nature of on-board computers; network communication equipment, namely, computer network adapters; vehicle radios; acidimeters for batteries; material for electricity mains, namely, electrical wire and electrical cables; electrical copper wire, insulated; integrated circuits; chips, namely, integrated circuits; electromagnetic coils; capacitors; variometers in the nature of variable transformers; couplings, electric; electric control panels; low voltage electrical power supply; Power supplies electrical; electrolysers; theft prevention installations, electric, namely, anti-intrusion alarms; batteries, electric, for vehicles; accumulator jars; battery boxes; plates for batteries; batteries for lighting; anode batteries; high tension batteries chargers for electric batteries; galvanic cells; galvanic batteries; grids for batteries; solar batteries; batteries for pocket lamps; batteries, electric; accumulators, electric; electrified fences.

Sunwoda Electronic Co. and Xwoda Electronic Con. Ltd | Date: 2011-04-19

Computers; laptop computers; computer peripheral devices; data processing equipment namely, couplers; notebook computers; sonar; intercommunication apparatus, namely, apparatus for transmission of communication; electric navigational instruments; video telephones; navigation apparatus for vehicles in the nature of on-board computers; electric satellite navigational apparatus; walkie-talkies; tape recorders; radios; audio and video receivers; vehicle radios; apparatus for games adapted for use with an external display screen or monitor; amusement apparatus adapted for use with an external display screen or monitor; headphones; accumulators, electric, for vehicles; batteries, electric, for vehicles; battery jars, namely, battery packs; battery boxes; batteries for lighting; high tension batteries; battery chargers; galvanic cells; galvanic batteries; batteries for pocket lamps; batteries, electric; solar batteries; acidimeters for batteries.

Tian Y.,Tsinghua University | Xia B.,Tsinghua University | Xu Z.,Sunwoda Electronic Co. | Sun W.,Sunwoda Electronic Co.
Journal of Power Electronics | Year: 2014

The power-voltage (P-V) characteristic of a photovoltaic (PV) array is nonlinear and time varying with the change in atmospheric conditions. As a result, the maximum power point tracking (MPPT) technique must be applied in PV systems to maximize the generated energy. The incremental conductance (INC) algorithm, one of the MPPT strategies, is widely used for its high tracking accuracy, good adaptability to rapidly changing atmospheric conditions, and easy implementation. This paper presents a modified asymmetrical variable step size INC MPPT method that is based on the asymmetrical feature of the P-V curve. Compared with conventional fixed or variable step size method, the proposed method can effectively improve tracking accuracy and speed. The theoretical foundation and design principle of the proposed approach are validated by the simulation and experimental results. Source

Tian Y.,Tsinghua University | Xia B.,Tsinghua University | Sun W.,Sunwoda Electronic Co. | Xu Z.,Sunwoda Electronic Co. | Zheng W.,Sunwoda Electronic Co.
Journal of Power Sources | Year: 2014

Accurate estimation for the state of charge (SOC) is one of the most important aspects of a battery management system (BMS) in electric vehicles (EVs) as it provides drivers with the EVs' remaining range. However, it is difficult to get an accurate SOC, because its value cannot be directly measured and is affected by various factors, such as the operating temperature, current rate and cycle number. In this paper, a modified equivalent circuit model is presented to include the impact of different current rates and SOCs on the battery internal resistance, and the impact of different temperatures and current rates on the battery capacity. Besides, a linear-averaging method is presented to calculate the internal resistance and practical capacity correction factors according to data collected from the experimental bench and saved as look-up tables. The unscented Kalman filter (UKF) algorithm is then introduced to estimate the SOC according to the presented model. Experiments based on actual urban driving cycles are carried out to evaluate the performance of the presented method by comparing with two existed methods. Experimental results show that the proposed method can reduce the computation cost and improve the SOC estimation accuracy simultaneously. © 2014 Elsevier B.V. All rights reserved. Source

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