Ni_xCo_1-x(OH)₂ xerogels were formed by sol-gel method under ambient pressure. The structure of these materials was characterized using N₂ (77 K) adsorption, XPS and XRD. Their capacitive performance was evaluated by using galvanostatic technique. The results show that the Ni_xCo_1-x(OH)₂ xerogels materials have a well-developed mesopore structure. The rate performance of the Ni_xCo_1-x(OH)₂ xerogels materials was greatly improved by Co impregnate, and the optimal amount of Co was 24%. The crystal structure of Ni_xCo_1-x(OH)₂ xerogels is the same as that of the β-Ni(OH)₂. The crystallite size of the Ni_xCo_1-x(OH)₂ xerogels will change largely except the amount of Co is above 20%. The electrochemical capacitor consisted with activated carbon and Ni_0.76Co_0.24(OH)₂ was cycled at a current density of 20 mA/cm², a coulombic efficiency above 95% and above 90% capacity retention after 100000 cycles were obtained. In the process long charge/discharge cycle, the crystallite size of the Ni_0.76Co_0.24(OH)₂ xerogels changes little, but the lattice parameter of the Co_0.24Ni_0.76(OH)₂ xerogels gradually shifts to the lattice parameters of the ideal β-Ni(OH)₂ crystal.

The use of mobile lng emergency units (MLEU) is an effective method to meet urgent gas supply demand. Current MLEU using ambient air vaporizer (MLEU-AAV) and gas fired water bath vaporizer (MLEU-GFWB) have a poor stability, and the MLEU-GFWB is expensive. This paper introduces a novel mobile LNG emergency unit with a heat storage vaporizer (MLEU-HSV). The working principle, conceptual design and techno-economic evaluation of the MLEU-HSV are outlined. The results show that the specific emergency gasification cost for large and medium-sized MLEU-HSV is comparable to MLEU-AAV, 2.23 yuan/Nm³ and 2.42 yuan/Nm³, respectively. They are about 0.1 yuan/Nm³ lower than that of MLEU-GFWB. The gasification intensity can reach 70 Nm³/(m²·h), comparable to that of MLEU-GFWB. These results suggest that MLEU-HSV be a promising alternative to the current technologies.

This bimonthly review paper highlights 100 recent published papers on lithium batteries. We searched the Web of Science and found 1416 papers online from April 1,2015 to May 31,2015. 100 of them were selected to be highlighted. Layered oxide and high voltage spinel cathode materials are still under extensive investigations for the structure evolution and modifications. Large efforts were devoted to Si based anode material. There are a few papers related to electrolyte additives, solid state electrolyte, Li/S and more papers for characterizations, modeling and analyzing the fading and thermal safety mechanism of the cell.

Due to environmental concerns and needs for energy saving, electric vehicles will become an important area of future development of automotive industry. Recent years have seen rapid development of battery thermal management technologies, which play a crucial role in the battery performance and life-span. Battery thermal management technologies can be classified into three categories of air-cooling, liquid-cooling and phase change materials (PCM) based technologies. This paper provides a review of recent developments in battery thermal management using PCM. Particular focus is on the use of PCM containing highly thermally conductive particles and PCM embedded in metal foams.

With the development of electric vehicles and electronic equipments, lithium-sulfur battery as a potential high-energy chemical power becomes attractive because of its high theoretical specific capacity of 1675 mA·h/g and high theoretical energy density of 2600 W·h/kg. However, the development of lithium-sulfur batteries inevitably has some challenges, including the lower ion and electronic conductivity of sulfur, poor cycle properties, the generated lithium polysulfide can be easily dissolved in organic electrolyte, which become a big barrier for the research and development of lithium-sulfur batteries. In this paper, research progress reported on cathode materials of lithium-sulfur batteries in recent years, the current status, problems and challenges of cathode materials of lithium-sulfur batteries are summarized. Lithium-sulfur batteries can not be in large-scale applications because its development bottleneck is hard to break out. Sulfur electrode material with low conductivity and poor cycle performance, may be improved by carbon coating and/or doping. However, due to the problems of cost and technology, the cathode materials for lithium-sulfur batteries are still in the experimental stage. Therefore, to explore a suitable way for industrial production of improved sulfur based cathode by carbon coating and/or doping technology is the focus of the future work.

Heat storage helps improve efficient utilization of solar energy and reduce energy consumption of traditional wood drying, thus contributing to the sustainable development of wood industry．This paper first outlines the basic principle of thermal storage technologies and their applications．Current state-of-the-art development in the area is then described particularly for wood drying using solar heat. Finally, an outlook of future development of the thermal storage technology in the field is given.

Due to intermittency and randomness of wind, the accuracy of wind power prediction is still low. With access of large-scale wind power to centralized grid systems, significant increase is expected in the burden of power system scheduling, leading to adverse effects to power control. This can be alleviated by using energy storage systems (ESS), which is able to time shift energy and power. This paper first describes the impact of uncertainty of wind power on the scale of wind power dispatching in terms of power system security. Then a time series regression model is proposed to predict wind power. A control strategy is put forward for ESS based on wind power prediction error interval. Finally, an assessment is made on the effectiveness of the strategy.

This paper describes a 150kJ/100kW directly cooled high temperature superconducting electromagnetic energy storage (SEMS) system recently designed, built and tested in China. The high temperature superconducting magnet is made from Bi2223/Ag and YBCO tapes, which can be brought to ~17K through direct cooling. Preliminary experiments have shown that the critical current of the superconducting magnet reaches 180A with a maximum energy storage capacity of 157kJ and a maximum central magnetic field of 4.7 T. The 150 kJ/100 kW SMES has been found to respond very rapidly to active and reactive power independently in four quadrants of an AC power system, with a response time of less than 10 ms. It is also shown that, in a dynamic simulated experiment, the SMES can effectively damp power oscillation due to line fault of line to ground at the generator terminal.

According to the sodium-nickel chloride battery data published by CESI and based on the discharge relaxation measurement, the parameters of second order RC dynamic model of the sodium-nickel chloride battery was identified. A simulation model was built and the simulation result shows that the parameters obtained is rather precise. The equivalent circuit model can well simulate its dynamic characteristics, and can be used for the battery monitoring and management system.

The MCO₃ precursor was synthesized via co-precipitation using Na₂CO₃ and C₃H₅O₃Na as the precipitation and complexing agents, then the mixtures of MCO₃ precursor and LiOH·H₂O were calcined at 950℃ to form the Li_1.2[Mn_0.52-0.5xNi_0.2-0.5xCo_0.08+x]O₂ (x=0, 0.02, 0.04, 0.06) series cathode materials. The influence of element content changes in Li_1.2[Mn_0.52-0.5xNi_0.20-0.5xCo_0.08+x]O₂ on the microstructure and charge-discharge properties of Li_1.2[Mn_0.52-0.5xNi_0.2-0.5xCo_0.08+x]O₂ cathode materials has been investigated. The results showed that the value of c/a for the lattice parameter is increased when the x value increases. When x is 0.02, the material showed the best properties with the initial discharge capacity of 261.0 mA·h/g, a capacity retention of 98.85% (189.9 mA·h/g ) after 100 cycles at 0.5 C and a discharge capacity of 157.6 mA·h/g at 2 C. With the further increase of x value (the rise of Co content), more 2g band of Co^3+/4+ overlapped with the 2p band of O^2- happens and it shows lower specific capacity and cycle ability.

A size designing method of battery with high mass specific energy and a battery mass formula were provided. Correctness and accuracy, usage and significance of the battery mass formula were proved and expounded respectively by an example . It was shown that there is minimum for the battery mass formula in its domain, and that theoretical basis for size designing battery with high mass specific energy can be obtained by calculating minimum of the battery mass formula.

During the design process of composite polymer electrolyte, the method which combines a structure load phase and an ion conductive phase was used to meet the demand of mechanical strength and electrical properties. The first step is choosing epoxy resin as matrix to guarantee good mechanical strength, then using different pore-forming agents to build connecting pore structure. By connecting pore to fill gel electrolyte or absorb liquid electrolyte to get ionic conductivity. According to the results, when the weight rate of epoxy resin:naphthalene:DBP:SiO₂ was 20:20:4:1, the sample shows the highest absorption ability for electrolyte and good mechanic properties. The ionic conductivity of samples is 1.6×10^-3 S/cm, which meets the demand of the application of a lithium ion battery.