Lithium sulfur (Li/S) is a promising candidate of next generation of rechargeable batteries because of its extremely high specific capacity and abundant natural resources. However, the safety issue might be one of the most important factors which hinder their practical applications. Here a highly effective flame-retarding additive, ethoxypentafluorocyclotriphosphazene (PFPN), is firstly applied in Li/S batteries to improve their thermal safety properties. The addition of about 5% (weight ratio) PFPN makes the highly flammable liquid electrolyte totally nonflammable. Furthermore, the addition of PFPN simultaneously reduces the polarization voltage and obviously enhances the rate capability of sulfur-based composite materials. All these results indicate that PFPN is a favorable flame inhibiting additive in conventional liquid electrolytes for rechargeable lithium sulfur batteries.

This bimonthly review paper highlights 100 recent published papers on lithium batteries. We searched the Web of Science and found 1679 papers online from April 1, 2016 to May 31, 2016. 100 of them were selected to be highlighted. Layered oxide and high voltage spinel cathode materials are still under extensive investigations for influences of doping, coating and interface modifications on their cycling performances. Large efforts were devoted to Si based composite anode materials and metallic lithium anode for analyzing the SEI There are a few papers related to electrolyte additives, solid state lithium batteries, Li/S batteries, Li-air batteries, and modeling, and more papers for the characterizations and calculations of doping to cathode materials, SEI and solid state electrolytes and batteries.

Abstract: Nano-Si/C composite materials made up of nano-sized Si and carbon, is considered can solve the problem of large volume variation and unstable SEI formation of Si anode upon cycling, which have always impeded the practical application of Si-based anode. Because the carbon can effectively accommodate strain release and stablize the electrode/electrolyde interface. In this report, the recent progress of nano-Si/C materials is briefly introduced. After continuous research and development, the rebounding, efficiency, compaction density and workability of low capacity composite materials (380～450 mA·h·g^-1) has reached the level of state of art commercial graphite material. The cycle and rate performance of high and ultra-high capacity materials (500～2000 mA·h·g^-1) has been significantly improved owing to the sophisticated structure design.

Carbon nanotubes with high electrical conductivity, thermal conductivity, outstanding mechanical strength, and unique morphology and structure, are used for promoting the performance of lithium-ion batteries. This paper reviews the latest progress in the study of carbon nanotubes which act as conductive additives, matrices of composite electrode materials, and current collectors in lithium ion batteries. The emphasis is to introduce the latest methods of application carbon nanotubes as conductive additives and composite matrices in electrode materials, as well as the effects of these applications on lithium storage capability, rate capacity and cycle life. There are also some challenges for carbon nanotubes widely used in the lithium-ion batteries, such as decreasing the production costs, inventing composite technique on carbon nanotubes for industrial manufacture, and improving the dispersion performance.

As high capacity and thermal stable anode materials, elemental phosphorus composites have been showing more and more interests for secondary batteries. This paper has reviewed the preparation of the composite materials of elemental phosphorus and the application in the lithium-ion battery and sodium-ion batterie, and analyzed the electrochemical properties and its problems. Study on the composite of elemental phosphorus should be pay attention to explore and surmount such questions that the preparation methods and modified materials.

The decomposition of traditional lithium-ion batteries at high voltage limit the development of high voltage lithium-ion batteries. Approaches to circumvent these challenges include (1) the design and synthesis of intrinsically stable electrolytes to tolerate high voltages, and (2) looking for suitable electrolyte additives. The latter approach is particularly appealing from the techno-economic perspective to stabilize the electrode/electrolyte interphase. This review summarizes the latest research progress on electrolyte additives for high voltage lithium-ion batteries. According to their types, the additives can be divided into six categories: boron-based additives, organophosphorus additives, carbonate additives, sulfur-based additives, ionic liquid additives, and other additives. The effect and working mechanism of the additives are generally described and discussed. The prospect of the high voltage electrolyte additives used in the future were also analyzed.

Lithium batteries have the highest theoretical energy densities among all electrochemical energy storage devices. Prediction of the energy density of the different lithium ion batteries (LIB) and metallic lithium ion batteries (MLIB) is valuable for understanding the limitation of the batteries and determine the directions of R&D. In this research paper, the energy densities of LIB and MLIB have been calculated. Ourcalculation includes the active electrode materials and inactive materials inside the cell.For practical applications, energy density is essential but not the only factor to be considered, other requirements on the performances have to be satisfied ina balanced way.

Li₄Ti₅O₁₂ as anode material of lithium ion storage battery has an outstanding performance in cycling and safety. With the analysis of SEM, FTIR, XRD and EIS, it was found that the degradation of NCM+LCO/LTO cell cycled at 1C and 2C rate is mainly happened at the cathode side. Because the interface film formed by the reaction of the cathode and electrolyte is unstable, it further consumes lithium ion in latter cycling. Besides, the gases evolved constitutes mainly CO₂ and C2H6, indicating that the moisture is strictly controlled in producing process and the electrolyte has been improved with some additives.

(1-ω%)LPOS·ω%(t-LGPS)(ω=3, 5, 7, 10) are prepared by mixing the glass precursor of sulfide solid electrolyte 75Li₂S·24P₂S₅·1P₂O₅ (LPOS) and Li₁₀GeP₂S₁₂ (LGPS) precursor in different proportions and sintering the mixture at 270 ℃ for 4.5 hours. The prepared 95%LPOS·5%(t-LGPS) presents the highest conductivity of 1.0×10^-3 S·cm^-1 at room temperature. The prepared novel solid electrolyte was characterized systematically by XRD, EIS and SEM, et al., furthermore, the probable mechanism of the conductivity enhanced has been discussed. The all-solid-state cell with a structure of LiCoO₂/95%LPOS·5%(t-LGPS)/Li shows a discharge capacity of 115.7 mA·h·g^-1 at 0.1 C and high capacity retention 80.38% after 20 cycles at 25 ℃, which are better than these of the cell use the LPOS as electrolyte.

The practical application of supercapacitors has been limited by the energy density, which could be effectively improved by matching the specific capacitance between the positive and negative electrode and designing an asymmetric organic supercapacitor. Herein, we synthesis activated hierarchical porous carbon (aHPC) supported polyaniline (aHPC@PANI) and aHPC supported poly(1,5-diaminoanthraquinone) (aHPC@PDAA) nanocomposites by an in-situ chemical polymerization method with aHPC as scaffolds and β-naphthalenesulfonic acid (β-NSA) as both soft-template and doping acid. As a result, both aHPC@PDAA and aHPC@PANI composites exhibit loose and porous structure with polymer nanoparticles deposited evenly on the aHPC surface, which are beneficial for the utilization and rate performance of active materials. Moreover, aHPC@PANI is used for the positive electrode, which delivers the specific capacitance of 256.7 F·g^–1 at a current density of 1 A·g^–1 (-0.6~0.8 V). And the negative electrode is based on the aHPC@PDAA, and its specific capacitance is 253 F·g^–1 at 1 A·g ^–1(–2～–0.6 V). The as-assembled aHPC@PANI//Et4NBF4-AN//aHPC@PDAA asymmetric organic supercapacitor achieves wide potential window (2.8 V), high energy density (65 W·h·kg^–1, 1.38 kW·kg^–1, based on total mass of aHPC@PANI and aHPC@PDAA), and excellent cycling stability (the capacitance retention is 90.2% after 5000 cycles).

The LiFePO₄/LiNi_0.8Co_0.15Al_0.05O₂ blend cathode material for lithium ion batteries was prepared by ball-milling to improve the electrochemical thermal stability of LiNi_0.8Co_0.15Al_0.05O₂. The crystalline structure, morphology and electrochemical performance were characterized by X-ray diffraction, scanning electron microscopy and electrochemical tests. The results showed that LiNi_0.8Co_0.15Al_0.05O₂ was coated by the LiFePO4 nanoparticals.  LiFePO₄/LiNi_0.8Co_0.15Al_0.05O₂ blend cathode material exhibited an excellent electrochemical thermal stability with 82.0% capacity retention after 100 cycles at 50oC, which was is much better than 72.9% of the pristine LiNi_0.8Co_0.15Al_0.05O₂.

Activated graphene/activated carbon composite electrodes were successfully prepared by the method of dry method of electrode preparation. The electrochemical performance of activated graphene/activated carbon electrodes was investigated using coin cell supercapacitor and soft package supercapacitor, respectively. Comprehensive results show that the activated graphene content of 10% (weight ratio) in composite is relatively reasonable. Compared to activated carbon electrode, the specific capacitance of 10% (weight ratio) activated graphene/activated carbon composite electrode increases by 10.8%. This work verified the applicability of activated graphene material in the commercial supercapacitor, and confirmed that the activated graphene is a kind of electrode material with high practical application value. But by now, the activated graphene has not really industrialization, its cost is much higher than that of commercial activated carbon. In the future, how to solve the engineering technical problem of activated carbon and reduce its cost are the urgent problems to be solved by the material industry.

As high temperature heat transfer fluids, hybrid nitrate salts play a promising role in application of concentrating solar thermal power system. In this study, the heat capacity of NaNO₃-KNO₃-LiNO₃ ternary hybrid nitrate heat storage materials were effectively enhanced by doping SiO₂ nanoparticles with aqueous solution method. With comparison of different mass ratio of nanoparticles, we found that lower mass ratio of nanoparticles has more effective enhancement on heat capacity. The effect of agglomeration of nanoparticles on heat capacity enhancement was also studied. By using polyvinylpyrrolidone (PVP), we reduced the agglomeration of nanoparticles and the dispersity of nanoparticles in nitrate salts was improved which showed furtherly enhancement of heat capacity of nitrate salt heat storage materials. Combined with the results above, we introduced the interface thermal resistance and semi-solid layer model, and the mechanism of heat capacity enhancement of nitrate salt materials by doping nanoparticles was discussed.

Using the Na₂SO₄, K₂SO₄ and MgSO₄ as raw materials. A new type of ternary sulfate molten salt was prepared by adding different content of MgSO4 in the range from 10% to 40% (weight ratio) to the binary eutectic salt of Na₂SO₄-K₂SO₄ The melting temperature, latent heat value, thermal conductivity, specific heat, decomposition temperature and thermal stability were tested by means of thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), Thermal constants analyzer, X ray diffraction and thermal cycle tests. Experimental results showed that the ternary sulfate molten salt had a melting point which was distributed between 667.5 ℃ and 669.7 ℃. Whose melting point were 160 ℃ lower than that of binary sulfate molten salt, the ternary sulphate molten salt with 30% (weight ratio) MgSO₄, had the highest latent heat value 94.3 J·g^-1, the maximum specific heat capacity was 1.13 J·(g·K) ^-1 between 720 ℃ to 800 ℃, thermal conductivity was 0.41 W·(m·K) ^-1, and the decomposition temperature was 1070 ℃, after 50 times thermal cycle tests, the latent heat value slightly declined by 4.34%, the melting temperature and phase composition maintained the constant, indicated the ternary sulphate molten salt with 30% (weight ratio) MgSO4 had good thermal stability. The research provided basis for sulphate salt, which could be applied to high temperature heat transfer and heat storage medium.

An alloy steel flywheel with 60 MJ storage energy at 2700 r/min rated speed was designed in this study, in order to achieve MW-level power output in the flywheel energy storage device of drilling rig power system. 35CrMoA steel was the selected material and manufactured into ‘H’ cross-section. The flywheel was 1600mm in diameter, 380mm in thickness and weighed 4000 kg. The core shaft was interference fitted with the hub locally to repeal assembly difficulty. While several cylindrical pins transferred the torque between flywheel and shaft instead. Finite element method (FEM) analysis evaluated these design ideas efficiently. The spoke formed thick inner and thin outer accorded with equal-strength design approximately. Besides, thicker flange benefitted to adjust mass distribution for larger rotary inertia. And the pins connection to transfer torque optimized local stress compared to traditional spline connection. The maximum stress in flywheel shafting system, owning 2.5 times' safety coefficient, was less than 500 MPa under the rated rotary speed. Flywheel energy storage (FES) device was debugged successfully in March 2016 with the energy density of 4.17 W·h·kg^-1 and the secific power of 250 W·kg^-1, achieving the functions of 150～200 kW charging and 500～1000 kW discharging. This project indicated that our country obtained the ability to develop a sigle FES equipment with MW-leveled power output.

A new type of hybrid capacitor was fabricated using lithium titanate (Li₄Ti₅O₁₂) with different conductive additives and activated carbon. Influence of conductive additives on electrochemical performance of hybrid capacitor was investigated. After using SEM and electrochemical performance analysis, the most outstanding conductive additives for Li₄Ti₅O₁₂ have been figured out. The results indicate that with the adding of super-P/VGCF, the hybrid capacitor can embraced the best performance. When testing at 0.1A·g^–1 and 2A·g^–1 the capacitor can be shown the highest capacitance (45.4F·g^–1 at 0.1A·g^–1) and best rate performance (91.5% at 2A·g^–1). Meantime the capacitor still maintains 93.2% of its initial capacitance after 10000 cycles at 0.5A·g–1.

 The high power fast charging characteristics of fast charging electric vehicle station will have enormous impact on the stability of the power gird, therefore the battery energy storage system(BESS) is considered to be configured in the fast charing electric vehicle station. Through the peak load shifting,BESS can reduce the transformer capacity allocation for the charging station and  release the adverse impact of high power fast charging on the power grid. Considering the current situation that a large number of retired power batteries need to be recycled urgently in China and combining with second-use battery energy storage system ,the economic evaluation model of fast charging electric vehicle based on overall costs and incomes is built. The maximization of annual net income is used as the objective function of the model and the improved genetic algorithm is used to optimize the model. Combined with case, the economical efficiency of fast charging electric vehicle station without BESS, with conventional BESS and with second-use BESS are analysed. The optimal capacity allocation scheme of second-use BESS is determined considering the economy and the effect of energy storage to reduce load.

Silicon-based anode materials have attracted a lot of interests due to their high specific capacities. In this paper, the SiOx & NG composite was measured as a high-capacity anode for lithium-ion batteries, and the effect of the SiO/C proportion on the energy density and cycle performance of full cell was investigated. The full cells with SiO/C composite in various proportions show different initial capacities and columbic efficiencies. Compared with natural graphite, SiO/C composites display a larger expansion. Moreover, the energy-density of full cell show an enhancement in a low SiO content but a gradual reduce with further increase of SiOx content, and the corresponding cycle performance of full cell decrease with the increasement of SiOx. When the proportion of SiOx is 4%, the energy density of full cell adds 1.2%, and the capacity retains over 80% after 500 cycles, which can satisfy the demands of commercial lithium ion batteries.

An economic assessment of the use of wind power for electrical space heating in winter was carried out. The study was done under current of electrical market in China, considering factors such as the curtailed wind power and electrical prices etc. An economic model was constructed for the electrical heating system using abandoned wind power and a number of key factors were analyzed. A case study on a Clean Heating Demonstration Project was conducted to analyze the effect of the abandoned wind power price on wind electricity economy, to verify the effectiveness of the proposed economic assessment.

Low-temperature hot water radiant system is widely applied due to its energy saving, providing comfortable environment and low heating temperature requirement. Here, based on the research on the phase change material (PCM) wallboard radiant system, a new kind of composite PCM wallboard is put forward, in order to improve the efficiency of energy storage. Heat transfer model of composite PCM wallboard is set up, and then the storage and release energy processes are conducted with the CFD software. The influence of composite PCM on the room environment is compared with that of the wallboard without PCM layer. Moreover, the influences of phase change temperature, the thickness of composite PCM layer on the wallboard surface temperature and heat flux are studied to account for the heat transfer process in the composite PCM wallboard. The results presented here can provide a theoretical fundamental for improving a comfortable heating system, and give a technology support to develop the application of low-grade energy.

 Aluminum plastic composite foil has become the common packaging material for soft package Li-ion battery, so it is worthy to study the influence factors of its heat-sealing strength to optimize safe capacity for battery. In this article, the heat-sealing strength of Al plastic foil after soaking in the electrolyte is tested by universal testing machine to discuss the influence of soaking ways(“soaking thoroughly” and “soaking partly”) and soaking time. It can be concluded that the heat-sealing strength and the failure modes under the different conditions(heat-sealing temperature and heat-sealing time) for “soaking thoroughly” is the same on basic, the achieved strength cannot reflect the real strength of heat-sealing zone. By contrast, the heat-sealing strength for soaking in bags can avoid the influence of the PA lay and the Al foil, so it is the better way to soak. In addition, the heat-sealing strength of Al plastic foil sinks after soaking, of which the trend is especially obvious for the specimens heat-sealed on lower heat-sealing temperature and shorter heat-sealing time. In experiments, it is found that during soaking the PH of electrolyte becomes lower, which may be one of the reasons for the sinking heat-sealing strength mentioned above.

 Various grouping ways of large capacity storage system (LCSS) has directly impact on resistance characteristics inside LCSS. Currently, researches on grouping manners of LCSS are still at initial stage. Large capacity vanadium redox battery storage system (LCVRBSS) is adopted for research analysis in this paper. By virtue of analyzing resistance characteristics of different grouping modes of single stack, butterfly algorithm is employed to obtain surface fitting for resistance characteristic of different grouping modes under various state of charge (SOC). Through simulation, the maximum fitting error is within 3.6%. As an aside, optimal grouping way of single stack can be achieved via minimizing resistance of single stack, conducted by particle swarm optimization algorithm.

This paper analyzes the generation power of the driving electric motor in the underway replenishment system. Based on the comparison of technical characteristics of battery, superconducting coil, flywheel and Supercapacitor, choses the Supercapacitor energy storage system to recoverying and utilizing of generation power. The author discusses the design and application of Supercapacitor energy storage system , calculate the basic design parameters . In the underway replenishment process, The distance of the supply ship and the receiving ship is changing, The electric motor of alongside replenishment equipment is repeatedly switched between the power-driven and the power-generated mode. The motor in the power-generated state feedback large generation power to the inverter DC bus, affect the normal work of the replenishment system and pollute the power grid. The Supercapacitor has high power density, high charge and discharge power, long service life and wide operating temperature range, ideally suited for use in the equipments that recoverying and releasing power repeatedly,for reducing system power and the pollution to the grid, also save energy.

Using a porous electrode theory of LiFePO₄ (LFP) lithium battery discharge behavior were discussed in detail and found with the discharge process and internal electrode electrochemical reaction from diaphragm lateral set side fluid move, and move past LFP basic completion of discharge process, electric cut-off electrochemical reaction stop in a certain position of the electrode, and not all of the LFP particles are completing the discharge. The effects of discharge rate, electrode conductivity and electrolyte diffusion coefficient on the discharge process were studied. With the increase of discharge rate, the distance of the electrochemical reaction is decreased, and the peak value increases, and the peak area becomes narrow. The increase of the polar plate conductivity can ensure that the electrochemical reaction is carried out from the side of the diaphragm, but the increase of the electrode conductivity cannot be further improved by the peak value of the electrochemical reaction to the depth of the electrode. The higher diffusion coefficient can ensure that all the active materials can react with electrochemical reactions. The above conclusions can provide an effective guide for the design and preparation of high performance LFP lithium batteries.

Cordierite-mullite composite ceramics were synthesised with calcined bauxite, talc and quartz as raw materials, and shaped to honeycomb configuration. A series of sealing agents (F series) were designed and tested for sealing AlSi₂₀ and Na₂SO₄ (phase change materials, PCM) within the ceramic honeycomb for heat storage applications. Thermal shock cycles between 200 and 900 ℃were performed for 30 times on the composite material (samples held at 900 ℃ for 12 h in each cycle). XRD, SEM, TG-DSC were used to study phase composition, microstructures and the thermal properties. The results show that Wa, Pa, D and σa of honeycomb ceramic after fired at 1440 ℃ are 2.38%, 6.32%, 2.65 g·cm^-3 and 25.77 MPa the phase compositions are cordierite, Mullite and a small amount of magnesium aluminum spinel. After 30 times thermal shock tests, the Wa and Pa increase slightly whereas D and σa decrease slightly. One of the sealing agents, F2, gives the highest shearing strength at about 2.53 MPa, which is also validated by SEM analyses. The SEM analyses also show that, after 30 times thermal shock tests, the PCMs have a good compatibility with the ceramic substrate with no leakage. TG-DSC studies also show that the phase change temperature of AlSi20/honeycomb energy storage composite material ranges from 571.7 ℃ to 583.5 ℃ with a peak temperature of 578.3 ℃.

The numerical simulation of a container type energy storage system velocity field and temperature field were carried out, according to standard k- model, D-O radiation model and lithium battery thermal characteristic. The simulating results of the basic case show that, compared with the stay away from the air conditioning area and adjacent air conditioning area, there are a big difference about the wind uniformity and the temperature difference between the battery modules. The basic case was optimized by adding the wind guide plate in the air channel and the structural adjustment. The simulating results of the optimized operating case show that, the improved flow field and temperature field distribution are more well-distributed, the temperature difference between the battery module is effectively reduced.

Based on electrochemical energy storage technology and industry development, introducing and analyzing the status in quo of electrochemical energy storage system standards at home and abroad. According to the existing standards system of electrochemical energy storage system, both in China and abroad, putting forward the requirements and roadmap for standard establishment. Finally, making recommendations for the direction and standard establishment of electrochemical energy storage system standards in the future in our country.

Wind energy storage is an effective way to improve the wind power quality, increase the wind power control and solve the problem of wind power grid connection. In this paper, the distributed wind energy storage system “One BESS for One Wind Turbine” is analyzed, and the design of the distributed wind energy storage system is discussed. The function of the data record, the monitoring interface and the report form of the wind energy management system is designed. The actual operating results show that the monitoring system can realize the functions of monitoring, historical data record, running mode setting, statistical analysis and report generation, etc. the system is reliable and can provide reference for the application of wind storage system.

Abstract：The design and performance of 100 kW/200 kW·h MH-Ni stationary energy storage system are reported. Due to its superior charge and discharge power characteristic, high safety, environmental friendliness, excellent low temperature performance and easiness to balance the single cells in a battery pack, MH-Ni battery is suitable for hybrid electric vehicles and stationary energy storage applications. In this storage system, MH-Ni cell of 100 A·h was designed, with the advantages of optimized power and energy, low impedance, wide operating temperature range and long cycle life The cells were connected in series to form a 12 V/100 A·h battery module and a sub-system of 380 V/100 A·h was assembled. A battery management system, with functions of low energy consumption, anti-interference, stable and reliable voltage, current, temperature detection circuit and heat dissipation, was designed and fabricated. An energy storage system was fabricated using the battery management system and six sub-system units.