The technology progress of anode materials for lithium ion batteries, such as natural graphite, artificial graphite, hard carbon, soft carbon, Li₄Ti₅O₁₂, Si-base materials, is reviewed. The advantages and disadvantages, performances and characteristic charge and discharge curves of different anode materials are presented. Market status of these anode materials are introduced, and the development tendency of the whole anode materials market is predicted. The industrialization status of these anode materials are also introduced, including mainstream production technology, application fields, leading corporations, etc. The development history of these anode materials, especially natural graphite and artificial graphite, and the early articles and patents of these anode materials in China are summarized. The common problems in the current anode materials industry are analyzed, several solutions are discussed, and the technology development is prospected.

Lithium-ion-battery (LIB) separators and their properties which affect the LIB's performance were introduced. The hot spots, safety related properties, new materials, ceramic coating and high wettability in LIB separators research were summarized. The technical requirements for LIB separators by sorting the LIB into two types (3 C battery and power battery) are also discussed. It is noted that 3C LIB separators need to have thinner thickness, higher porosity, higher heat resistance and better uniformity, while power LIB focus on increasing the energy density, expanding the electrochemical stability, enhancing the resistance to high voltage. The main progress in LIB separators' research were reviewed from the following four aspects: polyolefin modification, polyolefin-ceramic composite separator, new material systems and new process methods. Finally, the authors analyzed the status of separator industry in China, and suggested that more attention should be paid to independent research on technology and processes to ensure the quality of products with increasing of the productivity.

Binder is an important material for making electrodes, which can significantly influence the electrochemical performances of Li-ion batteries. Water-based binders have attracted much attention in recent research because the proper binders could enhance the adhesion with less amount. Moreover, binders also play an important role on improving electrochemical performance and restraining volume expansion. The application of water-based binder makes the production process more environmental friendly and cheaper. The application of water-based binder for cathode and anode in Li-ion batteries was reviewed in this paper. It was pointed out that the electrodes prepared with water-based binder possessed excellent performances and capacious application prospects. The features, merits and demerits for different kinds of binders were discussed. It shows that water-based binder can be used to replace the organic solvent-based binder polyvinylidene fluoride(PVDF). Finally, the developing trend of electrode binder was summarized.

Conventional lithium-ion (Li-ion) batteries become difficult to satisfy requirements of high-energy batteries due to environmental crisis as well as rapid developments of electronic and electromotive devices. The pursuit of battery system with high-energy density is the research hotspot in the domain of energy storage. Lithium-sulfur (Li-S) batteries are considered as one of the most promising energy storage systems due to high energy density, low cost, and environmental friendliness. However, the disadvantages of sulfur electrodes such as low electronic/ionic conductivity, large volume change during cycling, the dissolution of intermediates and the concomitant "shuttle effect", as well as dentrite formation in lithium anodes, hinder the commercialization of Li-S batteries. The employment of carbon-based materials in Li-S systems increases the electrode conductivity, buffers the volume change, and inhibits the polysulfide shuttle, presenting as an effective strategy in enhancing the electrochemical performance of Li-S batteries. In this paper, we review the most recent development of carbon-based materials applied in Li-S systems, including sulfur/carbon composites, carbon interlayers, self-standing/flexible electrodes and carbon-based anodes, present new insights of connection between carbon structures and improvement of sulfur electrochemical performance, and propose some critical issues in Li-S batteries as well as directions for its future developments.

With the emphasis on new energy and environment, the application of rechargeable lithium-ion batteries is gradually expanding in the field of electric vehicles and energy storage, which is bound to enhance lithium resource consumption. Under the current situation of the increasingly scarce lithium resources, it is inevitably so difficult to reduce the raw materials cost of lithium-ion batteries, which probably limits their large-scale application in energy storage. Nowadays, room-temperature sodium-ion batteries for large-scale energy storage have become a research hot topic due to a great deal of advantages such as abundant resources, low price, high energy conversion efficiency, long cycle life and low maintenance cost. In this work, analyses are carried on the electrode material selection and raw materials cost for room-temperature sodium-ion batteries in comparison with common lithium-ion battery systems. The results indicate that room-temperature sodium-ion batteries are promising alternatives in the field of large-scale energy storage from the viewpoint of battery economic perspective.

Increasing energy density of battery will dramatically extend the driving range of electric vehicles. "Strategic Priority Research Program" of the Chinese Academy of Sciences was initiated at the November 15, 2013. In this program, the lithium-ion battery of the 3rd generation, solid-state metallic lithium battery, lithium-sulphur battery and lithium-air battery have been investigated. The mass and volume energy density of 24 A·h Li-ion single cell, with nano-silicon carbon material as negative electrode and lithium-rich material as positive electrode is achieved as 374 W·h/kg and 577 W·h/L, respectively. The energy density of 8 A·h solid lithium battery using the polymer solid electrolyte at 60 ℃ is 240 W·h/kg, while the energy density of solid-state lithium battery based on the inorganic ceramic solid electrolyte is also 240 W·h/kg. The energy density of 37 A·h lithium-sulphur battery reaches 566 W·h/kg at room temperature and 616 W·h/kg at 50 ℃. The energy density of 5 A·h lithium-air battery is 526 W·h/kg. However, these batteries are still far away from practical applications in view of satisfying all required performances. Further comprehensive researches on fundamental science and key technology are needed. In addition, the increase of the energy density of batteries will also increase the safety concerns. Therefore, all lithium batteries containing solid electrolytes could become the final solutions for EV batteries.

Increasing energy density of battery will dramatically extend the driving range of electric vehicles. "Strategic Priority Research Program" of the Chinese Academy of Sciences (CAS) was initiated at the November 15, 2013. In this program, the lithium-ion battery of the 3rd generation, solid-state metallic lithium battery, lithium-sulphur battery and lithium-air battery have been investigated. The mass and volume energy density of 24 A·h Li-ion single cell, with nano-silicon carbon material as negative electrode and lithium-rich material as positive electrode is achieved as 374 W·h/kg and 577 W·h/L, respectively. The energy density of 8 A·h solid lithium battery using the solid polymer electrolyte at 60 ℃ is 240 W·h/kg, While the energy density of solid-state lithium battery based on the inorganic ceramic solid electrolyte is also 240 W·h/kg. The energy density of 37 A·h lithium-sulphur battery reaches 566 W·h/kg at room temperature and 616 W·h/kg at 50 ℃. The energy density of 5 A·h lithium-air battery is 526 W·h/kg. However, these batteries are still far away from practical applications in view of satisfying all required performances. Further comprehensive researches on fundamental science and key technology are needed. In addition, the increase of the energy density of batteries will also increase the safety concerns. Therefore, all lithium batteries containing solid electrolytes could become the final solutions for EV batteries.

The synthesis of cycle phosphazenes and their derivations the research progress of their applications in electrolyte and electrode materials of lithium ion batteries are reviewed, and related prospect is carried out. As lithium ion batteries widely used in the area of electric vehicle and energy storage, safety become more and more noticeable. Enhancing the safety properties of key materials is the one of the most important strategies to improve the battery safety. Due to the special constitute and structure of phosphonitrilic compounds, which endowed themselves efficient flame retardancy, chemical and electrochemical stability, the research is attracting more and more attentions. For their using as electrolyte additive and cosolvent, It is found that phosphonitrilic compound could not only improve the thermal stability and flame retard performance, but also benefit for the cycling performance of lithium ion batteries. Meanwhile, cycle phosphazenes could be used in the positive and negative electrodes to improve the safety of the cells. Above all, phosphonitrilic compound is a promising material either in fundamental research or practical use in lithium ion batteries.

Recently, there are intensive efforts to develop advanced separators for lithium-ion batteries for different applications such as electric vehicles and energy storage. This paper summarizes the requirements of battery separators and the structure and properties of five important types: ①polyolefin separators; ②modified polyolefin separators; ③composite separator; ④nano-fiber separator, and ⑤ electrolyte membranes. The performance requirements for lithium ion battery separator are introduced and the current research results of various types of power lithium ion battery separator are reviewed. The features and applications of the modified separators for lithium ion battery are introduced. It is noted that the safety related properties and uniformity are the key performances of battery separator. The outlooks and future directions in this research field are given.

With the rapid development of renewable energy in China, it is an urgency issue to solve the power accommodation and synchronization problems of renewable energy. Large-scale energy storage is known as the most effective way to solve this problem. Compared with the existed energy storage form, a hydrogen energy storage system consisting of electrical energy chain and hydrogen energy chain is proposed. The analysis is focused on the key technologies of hydrogen energy storage, including hydrogen production, hydrogen storage and transportation, hydrogen fuel cells. Key components and system performance of different types of hydrogen energy storage systems, including electrolytic cells, fuel cells and drogen storage materials, are also compared and analysed. The main demonstration plants of the system in Germany and France are introduced. Finally, the development trend of hydrogen energy storage system is presented.

In this study, the samples were soft packaged lithium iron phosphate cells, for the remaining capacity close to 80%. The safety performance of the low temperature -10 ℃ was studied. Compared the thermal runaway test results of the cells after the low temperature and room temperature cycling. The content of lithium and the thermal stability of the battery materials were analyzed. It showed that the capacity of cells cycled at the low temperature decreased rapidly. Differential thermal analysis and elemental analysis of electrode cell materials further showed that lithium metal appeared on the anode after low temperature cycling and the thermal stability of battery materials also changed. After an aging with full charge, all the cells after low temperature cycling produced gases, mainly CO and H₂. Compared with the fresh cells, the used cells with 80% remaining capacity shows obviously lower electrochemical and thermal safety performances. So the used soft package lithium iron phosphate cells should be avoided to run at low temperatures.

Recent developments in energy technologies have led to an increased effort in scientific research into the use of nitrate salts as an energy storage material in recnet years. However, little is known about on the structure of molten salts and the influence of impurities on the structure of molten salt mixtures have been seldom reported. The presence of impurities can impose impacts on the thermophysical characteristics of molten salts that cannot be neglected. This study examines the addition of SO₄^2- on the structure and hence properties of a mixed KNO₃/NaNO₃ salt with mass ratio of 1∶1 a Raman spectral meter and a X-ray diffractometer were used in the measurements under different temperatures. The results suggests that when the molten salt solidifies and crystallizes, SO₄^2- ions combine with Na⁺ preferentially, and Na⁺ ions exist in the form of solid solution. It was also found that SO₄^2- ions exist in the form of solid solution at the room temperature, and the structure of the mixed salts change significantly at 200 ℃ compared to that at room temperature, suggesting a solid-solid phase change during the heating procedure. The results also show that the state of solid solution of SO₄^2- breaks at about 200 ℃.

In this paper, we report a study on the preparation and characterization of microcapsules containing butyl acrylate (energy storage material) and carbon nanotubes, with urea formaldehyde resin as shell material. An emulsion-solvent evaporation method was used for the production of the capsules. Scanning electron microscope, Fourier infrared spectrometer, differential scanning calorimetry and the hotdisk based thermal conductivity meter were used to characterize the capsules. Effects of the microcapsulation and the addition of carbon nanotubes were investigated on the thermal storage performance. The results showed that the carbon nanotubes were uniformly dispersed in butyl stearate within the core of the capsules, and the latent heat of phase change material and heat c were improved. The microcapsules were spherical, and the stearic acid butyl acrylate were encapsulated completely, providing an improved thermal stability of the phase change materials. It was also found that properties of the capsules were affected by how the carbon nanotubes were dispersed, the size and quality of the carbon nanotubes used, and even the methods and apparatus used for the measurements.

For the large-scale energy storage applications, the cells need to be in series/parallel to get the required voltage and capacity. The inconsistency of the cells due to the manufacturing process and using is one of the main factors affecting the service life of energy storage unit. In the charging and discharging process of battery for long-term energy storage applications, the difference of the voltage of cells will gradually become larger, leading to the fading of battery or even failure. Various kinds of equalization circuits are applied to reduce the influence of battery inconsistency. In this paper, a comparison of several kinds of commonly used battery equalization circuit, including the energy dissipation balance circuit and non-dissipative equalization circuit was made, emphasizing on the working principle of the switched-capacity method and analyses its efficiency. It is noted that the balance efficiency of the switching capacitor method is related to the initial state of the battery and not to the capacitance values of the capacitor.

Flow frame is a core part of zinc-bromine flow battery. Flow channel model is established in order to estimate the performance of flow channel used in application. Based on numerical calculation and flow dynamic simulation on electrolyte, some issues are studied including flow distribution in channel, flow rate in 4 outlets, pressure drop and its influencing factors like viscosity and inlet flow rate. It shows that: 4 outlets have same flow rate while electrolyte is not uniformly distributed in sector area. The pressure drop in channel under 200 mL/min, 0.018 N·m is 22.3 kPa, and the pressure drop is in proportion to the viscosity to the power of 0.7 of electrolyte and the flow rate to the power of 1.3.

At present, in the petroleum industry, the design of the drive system for drilling rigs is largely conservative for safety reasons. A large redundant power capacity configuration is often adopted, and there is a lack of detection means to monitor the energy state during operation. The lifting unit of an oil drilling rig relies on potential energy load, which undergoes an cyclic operation and has the potential to recover, store and use the energy. In this study, a new detection device is proposed and developed. With such a device, real-time characteristics of the transmission system, power change and energy transformation are obtained experimentally during operation. Based on the experimental results and data analysis, it is found that the diesel engine adopted for the drilling rig is on the high side, leading to resource waste. There is therefore a potential for reducing the waste through better matching and/or improvement of the transmission system.

Two types of battery management modes were applied for LiFePO₄ battery packs used in 110 kV substation DC power system. The operation result indicated that LiFePO₄ battery showed capability of replacement of lead-acid battery and good float-charging characteristics. The voltage and the internal resistance changed with the SOC of the single cells and the battery packs presented a 3% capacity degradation per year. Suitable battery management mode kept a small voltage difference among the single cells and prolonged the cycling life of the battery packs.