Lithium-sulfur (Li-S) batteries, with low cost and environmental friendly active materials, have received great attention due to their superior theoretical specific energy of 2600 W•h/kg and 2800 W•h/L. However, many technical problems in both basic materials development and manufacturing technology exploration still exist and severely hinder the industrialization process of Li-S batteries. From the perspective of industrial applications, this review summarizes the current problems and solutions with respect to safety, cycle-lifetime and energy density of Li-S batteries. Lithium metal heterogeneous deposition is proposed to be the main reason of batteries volume expansion. Based on investigation of cost and application requirement, industry-research cooperation and continuously technology innovation are necessary to achieve practical application.

This bimonthly review paper highlights 100 recent published papers on lithium batteries. We searched the Web of Science and found 2100 papers online from Dec. 1, 2016 to Jan. 31, 2017. 100 of them were selected to be highlighted. Layered oxide and high voltage spinel cathode materials are still under extensive investigations for studying Li+ intercalation-deintercalation mechanism and evolution of surface structure, and the influences of doping, coating and interface modifications on their cycling performances. Large efforts were devoted to Si based composite anode materials for analyzing the mechanism for Li storage and SEI formation. In-situ technologies are used to analyze the kinetic process and SEI and theoretical work covers the machnism for Li storage, kinetics, SEI and solid state electrolytes. There are a few papers related to electrolyte additives, solid state lithium batteries, Li/S batteries, Li-air batteries, and modeling.

Magnesium chloride hexahydrate (bischofite) has a phase transition temperature at about  117 ℃ with a phase change enthalpy of 160 kJ/kg. Such a material is non-flammable and has a high thermal conductivity and low price, and is therefore regarded as a promising phase change material (PCM) for medium temperature thermal energy storage applications. This paper aims to provide a state-of-the-art review on thermophysical properties of the material, including phase transition temperature, phase change enthalpy, heat capacity, thermal conductivity and density. Potential problems are identified for using the material as a PCM, including the extent of supercooling, phase separation, corrosion, and hygroscopicity of hexahydrate magnesium chloride. Discussion is made on possible solutions to these problems. It is concluded that good cycle stability could be achieved if a suitable nucleating agent and a thickener are used. Potential applications of the material as a PCM or as part of PCM mixtures are discussed.

Low thermal conductivity is one of the primary disadvantages of organic based phase change materials, which is the main reason behind the slow charging/discharging kinetics and restricts the practical applications of this type of materials. Recent research has shown an increased interest in the use of carbon materials, which not only have a high thermal conductivity, but also can be used as an adsorption carrier or a filler of organic PCMs. In this paper, we shall review the characteristics of carbon materials particularly microporous carbon, carbon fibers and carbon nanomaterials, and the use of these materials for the enhancement of thermal conductivity of organic based PCMs. We shall show that microporous carbon materials not only can enhance the thermal conductivity of organic PCMs, but also act as an encapsulation matrix for organic PCMs. Carbon nanomaterials appear to have great advantages in terms of thermal conductivity enhancement and nano-enhanced phase change processes, but this aspect is still in the early stage and requires extensive future research.

The recent development of pre-lithiation technologies in lithium-ion battery, lithium-sulfur battery, lithium-air battery, lithium-ion capacitor and other kind of new energy storage systems were summarized. The pre-lithiation strategies mainly include in-situ lithium-doping, interfacial contact reaction with lithium-metal, electrochemical and chemical lithiation, etc. It can efficiently ameliorate several challenging problems: (i) compensating the initially high irreversible capacity of anode in lithium-ion battery; (ii) solving the lithium consumption and safety issue of metallic lithium anode in lithium-sulfur/air battery; (iii) addressing the anodic lithium compensation in lithium-ion capacitors; thereby giving rise to enhanced electrochemical performances. However, a series of key issues, including the formation of solid electrolyte interface film on the electrode surface, growth of lithium-dendrite, electrolyte decomposition, and electrode internal-heating after the pre-lithiation, may influence on the energy/power density, cycle life and safety of energy storage systems. Full knowledge and understand of their correlations and interaction mechanism is strongly demanded to seek a simplified strategy for an accurate control in lithium compensation and then guarantee its scalable application. Therefore, it is rather significant to retrieve relevant literatures and summarize the pre-lithiation applications in energy storage systems for understanding the progress more comprehensively, thereby providing academic reference and theoretical basis for the further development in relevant and other kind of power system (e.g., sodium battery).

An Accelerating Rate Calorimeter was employed to study the heat release of lithium iron phosphate battery with different ageing status under adiabatic condition. Thermal behavior of lithium iron phosphate battery charged and discharged at 1C was researched，and the influence of cycle number, cycle rate, storage time and storage temperature on the overcharge test of lithium iron phosphate battery was studied. With the increase of the cycle numbers, the average power of the battery charge-discharge and overcharge increases. The raising range of the temperature and average heat power of the battery cycled at 1C is decreased, compared with that of battery cycled at 0.5C. This may be due to the decomposition of the electrolyte and the formation of a thick surface film, leading to the reduction of the total heat and average power, when the battery is cycled at high rate. With the increase of the storage time at the high temperature, the average power of the battery charge-discharge and overcharge increase as well. Furthermore, the raising range of the temperature and average heat power of the lithium iron phosphate battery with 100% SOC full power of the battery is smaller than that of battery with 50% SOC, which may be related to the stronger decomposition of the electrolyte at high state of charge. In the case of similar capacity loss, the influence of storage on the average power of the charge-discharge and the overcharge for the lithium iron phosphate battery is greater.

Second use of retired EV batteries not only effectively reduces costs of EV users, but also provides an alternative energy storage for the power system and helps mitigate the negative environmental impacts of EV batteries. Although some organizations attempted EV battery second use via demonstrations, the real potential of retired EV batteries and associated economic analysis are still insufficient. This paper therefore estimates the energy storage potential of retired EV batteries in China and conducted cost analysis accordingly. The study shows the large potential of retired EV batteries can be realized through improved battery module standardization and its cost benefit will be realized gradually along with the growth of the market.

The recently research for secondary utilization of VRLA Battery mainly refer to scrapped batteries disassembling, classifying, plate melting and plastic recycling technology to produce the raw materials In this paper, we discussed the feasibility of applying secondary utilization of VRLA Battery in the power system, which have been repaired with scientific method, to several scenes such as family storage etc. This paper first analyzes the causes of premature battery failure is lack of water and sulfation, and then briefly introduces the newest industry standards recommend repair technique, which can effectively solve the problem of water shortage and sulfation, and then recover the battery capacity and reduce the internal resistance, also analysis the feasibility of the application of VRLA battery after repaired in energy storage; Finally, We also discussed the application schemes of applying recovered valve regulated lead-acid batteries in the field of domestic photovoltaic energy storage, household energy storage and energy storage power station. And the future of secondary utilization of VRLA Battery using in these areas is prospected as well.

A vacuum adsorption method was used to make ceramsite particles to absorb capric acid-stearic acid based phase change materials (PCMs).These, upon subsequent surface sealing with silica sol, gave shape-stable encapsulated PCM particles. These encapsulated particles were then used as aggregates in cement formulation to obtain composite PCM concrete. The composite PCM concrete was characterized for their thermal and mechanical properties. The thermal storage performance of the composite PCM concrete was studied though contrast experiments in a model room. The results indicate that the composite PCM concrete has a good thermal stability demonstrated through 600 thermal cycles. At a load of 60% (by mass) composite PCM particles in the aggregates, the compressive strength and flexural strength of the concrete is increased respectively by 22.3% and 13.2% after 600 thermal cycles. The model room contrast experiments showed that the centre and interior average temperatures of the model house are 5 ℃ and 6 ℃ lower than that of the ordinary model room, with the phase change process lasting approximately 25 minutes. Analyses suggest when a concrete wall of 202 mm thickness is mixed with 4.20 kg/m2 PCM composite particles, it could achieve the same thermal insulation effect as a 282 mm thickness wall, illustrating the substantial enhancement of thermal storage capacity of the wall through the use of PCM.

As a frequently-used electrode material of the vanadium redox flow battery (VRFB), carbon felt (CF) supplies the redox reaction with places which is of great importance in determining the battery performance. However, due to the poor electrochemical activity for vanadium redox couples and the limited efficient reactive area, the performance of VRFB is limited greatly. Graphene oxide (GO) nanosheets with high specific surface area and abundant oxygen functional groups have been used to modify carbon felt (CF) by a simple physical adsorption method in this paper. And the electrochemical performance of the prepared GO/CF as the positive electrode in a VRFB has been investigated. The results show that after introducing GO nanosheets, the corresponding electrochemical surface area (ECSA) along with the wettability are greatly improved. Morever, according to the cyclic voltammograms (CV) and electrochemical impedance spectra (EIS) results, the improvement of the electrochemical response is mainly caused by the enlargement of the ECSA, however, the electrocatalytic activity of the GO/CF electrode has changed little. In addition, the charge/discharge results demonstrate that VRFB with GO/CF as its positive electrode shows higher battery efficiencies and favorable multiplying power performance.

Energy storage technology, which has become a hot spot in the international industrial competition, is the key support of smart grid and new energy development. Lithium ion battery is considered to be one of the most promising technologies in the field of energy storage because of its high energy density, small self-discharge and long cycling life. However, the lack of relevant standards hinders the development of lithium ion battery energy storage system in a certain extent. In view of this problem, we carried out a series of multi - level and multi - disciplinary standards collection and did some researches on their relations, and then studied on the application of standards in the near field if used in the energy storage system, combining with the characteristics of the application and safety assessment requirements of large energy storage battery. These studies may have positive significance for the promotion of lithium ion battery energy storage system in the future.

A novel cogeneration system of hydrogen and power is designed to solve the energy storage problem faced by both photovoltaic and solar thermal generation technologies. In this system, solar energy collection, photovoltaic generation, solid oxide electrolysis cell (SOEC) and solid oxide fuel cell (SOFC) are synergistically combined. A simplification of solar insolation curve was made before thermodynamic calculation. Based on the simplification, it shows that 1 MW system consists of 8.407 MW photovoltaic system, solar thermal collector with heating power of 6.756 MW, SOEC system with hydrogen produce rate of 0.0698 kg/s and 1 MW SOFC system. Power generating efficiency can reach 9.4% throughout the day, which partly demonstrates the feasibility of the system. In addition, oxygen can be produced in the system, which can be further utilized. Moreover, high temperature steam electrolysis which significantly reduces the electric energy consumption, provides a potential pathway for the interconversion of electricity and hydrogen. This method can be used to stockpile the electrical energy harvested from fluctuant renewable energy sources.

 With the progress of energy storage technologies and the expansion of energy storage application scenarios, the degree of attention for energy storage is increasing. In view of both the domestic energy storage technology and standards at an early stage of development, quantifying coupling degree of energy storage technology and standard can effectively help sort out obstacles to promote healthy and steady development of China's energy storage industry. This paper put forward an energy storage technology and standard evaluation system, develop a coupling model, and finally form a coupling analysis method of energy storage technologies and standards. Using this method, this paper analyze domestic typical energy storage technology and storage standards, results show that coupling degree is at a medium level but entire energy storage industry is still at a low level.

Currently, it lacks of research for the energy consumption distribution state and drive efficiency of oil rig mechanical drive system in working state. After acquisition data using special data detection device on Zhongyuan Oilfield well No.wen-409, mass real time data about running & power state changes of the drilling rig in the tripping operation was analysis. It shows that the load has periodic change and impact in drilling rig hoisting system at operation. In order to adapt to the impact load, the power capacity configuration of diesel engine of drilling rig is on the high side and the transmission efficiency is low level (38%—54% for trip-out, 41%—59% for trip-in). There is plenty of room for energy saving improvement in transmission system.This research providing basic experimental data for mechanical drive systems energy recovery and utilization and peak load regulating technology.

In wind power generation system, the output power will occur pulse wave which will influence the stabilization of the whole system, due to the variation of the wind direction and wind power. The energy storages system can smooth the fluctuation of output power and improve the stabilization of the generate electricity system. This paper analyzed the development of the compose energy storage system in the wind power generation system, and then proposed a kind of the composite energy storage system, established the model of this composite energy storage system in the PSIM. Through simulation experiment, it is showed that the system can easily smooth the fluctuation, when the frequency of the input power is 0.2～0.9 Hz, and the reality control and drive circuit of the composite storage system was tested.

A phase-change material (PCM) is a substance that melts and solidifies at a certain temperature range with little change of temperature, whilst releasing/absorbing a certain amount of heat called latent heat. Because of some unique properties, PCMs have become a research focus in recent years. This paper provides a brief review on some important thermal properties and behavior of PCM including latent heat, phase transition temperature and heat transfer coefficient associated with the use of PCMs. A basic model of PCM is then introduced for assessing the use of PCM in buildings. Energy saving due to the use of PCM in indoor applications is then analyzed and a concise method for the calculation of the amount of PCM for interior temperature control is presented.

Based on the Derwent Innovations Index database (DII) and Patent Analysis Online System of Chinese Academy of Science, this paper analyzed the annual distribution of applied patents, technical research, main competitive countries and patent applicants, etc. At the same time，the paper focused on the patents applied in China. We got the overall situation of patents through this analysis in order to provide some reference for science & technology innovation and industry development of inorganic solid electrolyte lithium-ion battery in China.

With the development of consumer electronic products and clean-energy vehicles, lithium-ion battery has been paid more and more attention by each and every country. As the key component of the lithium-ion battery, electrolyte of which the selection for different materials and various electrochemical performance, has an important effect on the electrochemical performance, safety performance and life span of the battery. In order to review the development and distribution of electrolyte for lithium-ion battery, patents from domestic and overseas on the electrolyte for lithium-ion battery filed are analyzed, based on the searching results from the Derwent Word Patent Index databass(DWPI) and China Patent Abstract Database(CNABS). Based on this results, this report focuses on the analysis of the aspects of patents application trend, distribution of the main technical fields for various countries or districts and major applicants in worldwide and China. The results show that Japan has an absolute advantage in the field of electrolyte for lithium-ion batteries, followed by Korea and China. China has being closed to the developed countries on the number of patents, however，it lacks of the foundation and core patents pack. In the various technical fields, electrolyte salt, organic solvent and additive have formed the inherent pattern, the development of new products and the mixture collocation becomes a breakthrough way. For the domestic important applicants, the decentralization of industry and lack of a number of leading enterprises are observed. At the same time, the industrial-academic-research cooperation may become another opportunity for development with the coexistence of enterprises and universities. Some suggestions are put forward on the development and distribution of patents of electrolyte for lithium-ion battery for our country in the future.

 Lithium-ion battery is the most promising and efficient secondary battery, and is also the fastest development chemical energy storage power supply. It has become a hot competition in every country of world. Patent technology can reflect the current situation and process of the innovation and development of a technical field, which is an important information source for competitive intelligence. From the perspective of patent analysis of the lithium-ion battery energy storage technology, to understand the development trend of lithium-ion storage technology, it may provide references for the strategic decision of our government and enterprises.