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LiNi0.5Co0.2Mn0.3O2 is becoming the dominating cathode material in lithium ion batteries, which have degradation issues after cycling due to Li+ loss and phase changes. But there is no effective method to solve this problem. Here, we offer an innovative method to regenerate degraded nickel-manganese-cobalt cathode particles to obtain new active particles. The results show that the regeneration materials display the discharge capacities of 162.0 mAh/g at 0.1 C. When cycled at 1 C, a highly reversible discharge capacity of 128.6 mAh/g can be obtained after 100 cycles with capacity retention of 91.9%, which is comparable with commercial LiNi0.5Co0.2Mn0.3O2.

Polymer-based dielectric capacitors play a notable part in the practical application of energy storage devices. Graphene oxide (GO) nanosheets can improve the dielectric properties of polymer-based composites. However, the breakdown strength will greatly reduce with the increase of GO content. Hence, the construction of sandwich structure can enhance the breakdown strength without reducing the dielectric constant. Herein, single-layered and sandwich-structured poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) nanocomposites with low content of GO nanosheets (＜1.0 wt.%) are prepared via employing a straightforward casting method. Compared with the single-layered composites and pure P(VDF-CTFE), the sandwich-structured composites exhibit comprehensively better performance compared. The sandwich-structured composite with 0.4 wt.% GO nanosheets show an excellent dielectric constant of 13.6 (at 1 kHz) and an outstanding discharged energy density of 8.25 J/cm3 at 3400 kV/cm. These results demonstrate that the growth of the dielectric properties is owing to 2D GO nanosheets and the enhancement of breakdown strength due to the sandwich structure. The results from finite element simulation provide theoretical support for the design of high energy density composites.

In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization, activation and post-nitrogen doping into one process. This preparation method can form particular hierarchical porous structure without using any sacrificial templates. The experimental results show that the nitrogen doped clews-like hierarchical porous carbon materials possess a relatively high specific surface area of 815 m2/g with the nitrogen content of 10.58 at%. The electrochemical properties show that the resulting sample delivers 258 F/g at a 0.5 A/g and excellent capacity retention of 79% at 20 A/g. After conducting 10,000 charge-discharge cycles at 10 A/g, the capacitance retention of 98.3% is achieved. These intriguing results demonstrate that the obtained nitrogen doped clews-like carbon materials will be promising electrode materials for supercapacitor and other energy storage devices.

Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) composed of 2H + 3R graphite phase with more uniform size were used as anode material and a new binder (WRA268) was used. The tests results show that at 0°C, MG11 using conventional binder (styrene butadiene rubber, SBR) attains 66% of reversible capacity retention rate, and synthetic graphite (FSN-1) using WRA268 as binder attains 76.9% of reversible capacity retention rate, but it attains 34% for the FSN-1 using SBR as the binder. These results show that MG11-WRA268 is promising materials using for battery in cold areas such as Tibet.

The spinel Li4Ti5O12 (LTO) has been doped by Ca2+ via a solid-state reaction route, generating highly crystalline Li3.9Ca0.1Ti5O12 powders in order to improve the electrochemical performance as an anode. The structure changes, morphologies, and electrochemical properties of the resultant powders have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and cyclic voltammetry (CV), respectively. Crystal structure and composition were analyzed, and results were obtained with various tests of LTO. Electrochemical measurements revealed that Li3.9Ca0.1Ti5O12 anodes exhibit better rate capability, better cycling stability, and a higher specific capacity than pure LTO anodes.

The highly uniformed hybrid carbon material has been prepared by in-situ growth carbon nanotubes (CNTs) from metal organic frameworks, with the cobalt species as the catalyst for CNTs growth and dicyandiamide (DICY) as a sacrificial agent for the formation of graphitic carbon. The CNTs with extraordinary conductivity supply more electron transport to the cathode and make much more sense in enhancing the rate performance of the sulfur cathode. In the matrix, cobalt nanoparticles and heteroatom nitrogen can help in immobilizing sulfur species, leading to the improvement of polysulfide shutting. Moreover, the increased specific surface area and mesoporous channel enhance the sulfur loading and facilitate electrolyte diffusion. On integrating these fascinating benefits into one electrode material, as a result, the hybrid composite (CNT@Co N C/S) cathode presents a high initial capacity of 1316.1 mAh/g at the current rate of 0.1C. Even at high current rate of 5C, a decent capacity of 620.7 mAh/g can still be achieved. The capacity of hybrids materials can be maintained at 970 mAh/g after 500 cycles at 0.2C, and a capacity retention of 79.8%, revealing it great potential for energy storage application.

Lithium-ion battery energy storage (LiBES) in grid is becoming more important for China’s energy revolution. Based on the study on fire development characteristics of LiBES, there are several key parameters on fire extinguishing device components yet to be verified before the development of efficient and reliable fire extinguishing devices in LiBES. to ensure the safe operation of the energy storage system. This report focuses on safety mechanism, design technology, standard system and firefighting of LiBES. Therefore, it intends to analyze the fire safety conditions of container LiBES in grid. This report is useful to improve the safety performance of the container-type LiBES, and it also has a significant social and economic benefit prospect, which has important theoretical practice and practical significance.

This paper summarized the recent developments in temperature-tolerance power supply for grid equipment, through the theoretical prediction, design synthesis and verification of key material systems, cell structure design, core mechanism and battery preparation engineering process, this report can develop batteries suitable for power source in grid equipments in low temperature regions to meet Xinjiang Power Grid. The demand for technology to achieve the leap-forward development of grid power quality services.

In recent years, the influence of dust on the external insulation of power system can not be ignored, but there are not many related researches at home and abroad. In order to study the discharge characteristics under dust environment, this paper selects the rod-plate gap as the research object and builds the dust simulation experiment. The platform is used to conduct experimental research on AC discharge characteristics, and the influence of factors such as gap distance and dust volume fraction on the AC-discharge of the rod-plate gap is obtained. When dust volume fraction is relatively small, AC breakdown voltage of the tip-plate gap decreases with increase of dust volume fraction And the voltage increases with increase of dust volume fraction when sand dust volume fraction is larger. It can be considered that there is a certain dust volume fraction (between 0.5% and 4%), so that the AC gap breakdown voltage is the smallest, and the volume fraction is independent of the gap distance. It can be considered that there is a fixed dust volume fraction (between 0.5% and 4%) that minimizes the gap AC breakdown voltage, which is independent of the gap distance.

Polypyrrole encapsulated nickel nanorods (PPy@Ni) have been prepared by electro-polymerization using Ni nanorods as template. PPy@Ni were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectrometer, Fourier transform infrared (FTIR) spectra and vibrating sample magnetometry (VSM). The maximum saturation magnetization of PPy@Ni was up to 44.6 emu g-1. Further, PPy@Ni was used as the additive for the conductivity improvement in polymer matrix. Experimental results showed that the electric conductivity reached 1.8×10-3 S m-1 when 5% PPy@Ni was added in the poly(urethane acrylate) matrix by applying a magnetic field. Further tests showed that when the additive concentration increased from 0.1% to 5%, the correspondence saturation magnetization increased from 15.1 emug-1 to 31.3 emug-1. This work provides new light on controllable fabrication of conducting polymer by adding magnetic alignment conductive additives.

Uncontrollable Li dendrite growth and unstable SEI during repetitive Li deposition–dissolution processes severely impede the practical application of lithium metal batteries (LMBs). Herein, we create a novel artificial SEI layer by using liquid metal with self-healing property. The liquid metal could effectively facilitate the stable SEI layer formation by virtue of its self-healing property and regulate Li ion flus and inhibit the Li dendrite growth in the deposition process of Li. Electrochemical studies show that the LMNP-Li|LTO full-cell exhibits a superb rate capability and an excellent long-term cycling stability. This work offers a novel approach to achieve a stable Li metal anode with long cycle life.

PbTiO3 nanorods with tetragonal phase were synthesized by hydrothermal method and heat treatment, and temperature-dependent electrical transport properties of individual PbTiO3 nanorod were investigated. The results show that the conductivities of PbTiO3 nanorods are gradually enhanced with temperature increasing from 77.4 to 295[Formula: see text]K, and exhibit the typical nonlinear I–V characteristics. The barrier height between Au electrode and nanorod is reduced from 0.137 to 0.088[Formula: see text]eV with increasing bias from 0.2 to 1[Formula: see text]V. The corresponding values of thermal activation energies are 0.172 and 0.06[Formula: see text]eV below the conduction band for 180–295 and 77.4–180[Formula: see text]K, respectively. This semiconductor-like behavior may result from the larger number of surface defects or localized states in the amorphorized PbTiO3.

In this paper, the optical technology is used to monitor ESDD near insulators on transmission line. This technique is based on the light energy loss and the distribution of optical field in the dielectric waveguide. Under the same measure environment, there has the certain correlation between the ESDDs of the polluted insulators and the ones of the quartz glass rod. Based on the experimental results, artificial neural networks (ANN) has been developed to model the relationships between ESDD by the optical technology and the measured ones. The contrasts reveal that the ANN-calculated ESDDs have the same corresponding with the measured ones for a practical system.

There has been a significant interest in many technical applications and natural phenomena concerning two-phase mixture discharges (TPMDs). Few studies have focused on the influences of different macroparticles on TPMDs. The dielectric constant is usually considered to be the only factor affecting the discharges, but in this paper, 21 kinds of different dielectric materials were used to investigate the effects on TPMDs. By the experimental results, this paper reveals the effects of macroparticle sizes, and the dielectric constant has little influence. When the diameter of TPMs is less than about 0.01 mm, the percentage of the selection of TPMs is always smaller than 50%, the discharge path selects the air but TPM, and the breakdown voltage is higher than that in air. However, when the diameter is greater than about 0.1 mm, the conclusion is opposite. When the diameter is in the range of 0.01-0.1 mm, the TPMDs have a polarity effect. The dipole-enhanced approximation model is applied to explain the experimental phenomena. It is very important in TPMDs that the macroparticle dielectric constant, the saturation charge, and the adsorption/desorption process on the material, except the effects of TPMDs, are highly correlated with the macroparticle sizes.

Three kinds of water mist with different droplet sizes are applied to understand the effect of droplet sizes on the initiation and propagation of discharges in a nonuniform field at atmospheric pressure. Based on the measurement of droplet sizes in three mists and the volume fraction of water droplets, effect of droplet sizes is demonstrated by directly comparing the percentages of the discharge path in mist at the different positions with those in air. It can be concluded that the mist with smaller μm-droplets has the negative impact on the initiation and propagation of discharges; the mist with larger μm-droplets has the inhibited effect on the starting and growth of positive discharge but has the contrary effects on negative discharge.

At pressure 1.0–4.0 GPa and temperature 1073–1423 K and under the control of oxygen fugacity (Mo+MoO2, Fe+FeO and Ni+NiO), a YJ-3000t multi-anvil solid high-temperature and high-pressure apparatus and Solartron-1260 impedance/Gain-Phase analyzer were employed to analyze the electrical conductivity of lherzolite. The experimental results showed that: (1) within the range of the selected frequencies (103–106 Hz), either as viewed from the relationship between the real or imaginary part of complex impedance and the frequency, or from the relationship between modulus, phase angle and frequency, it can be seen clearly that the complex impedance has a strong dependence on frequency; (2) with the rise of temperature (T), the electrical conductivity (σ) increased, and Lg σ and 1/T follows the Arrhenius relationship; (3) with the rise of pressure, the electrical conductivity decreased, and activation enthalpy and temperature-independent pre-exponential factor decreased as well. And the activation energy and activation bulk volume of the main charge carrier in the lherzolite have been obtained for the first time, which are 1.68±0.02 eV and 0.04±0.01 cm3/mol, respectively; (4) under the given pressure and temperature, the electrical conductivity tends to increase with increasing oxygen fugacity, and under the given pressure, the activation enthalpy and pre-exponential factor tend to decrease with the rise of oxygen fugacity; (5) at 2.0 GPa and the control of the three solid buffers, Mo+MoO2, Fe+FeO and Ni+NiO, the exponential factors of electrical conductivity variation range with oxygen fugacity are 1 3.19 - 1 3.67 , and the theoretical model for the relationship between the electrical conductivity of lherzolite and the oxygen fugacity under high pressure has been established for the first time; (6) the electrical conduction mechanism of small polarons provides a reasonable explanation to the variation of conductivity of lherzolite with oxygen fugacity.

At 1.0–4.0 GPa and 11213–1473 K and under oxygen fugacity-controlled conditions (Bi + NiO, Fe + Fe3O4, Fe + FeO and Mo + MoO2 buffers), a YJ-3000t Model six-anvil solid high-pressure apparatus and a Sarltron-1260 Impedance/Gain-Phase analyzer were employed to conduct an in situ measurement of the electrical conductivity of single crystal olivine. Experimental results showed that: (1) within the range of experimentally selected frequencies (103–106 Hz), the electrical conductivity of the sample is of great dependence on the frequency; (2) with the rise of temperature (T); the electrical conductivity (σ) will increase, and the Arrenhius linear relationship is established between 1gσ and 1/T; (3) under the control of oxygen buffer Fe + Fe3O4, with the rise of pressure, the electrical conductivity tends to decrease whereas the activation enthalpy and independent-of-temperature preexponential factor tend to increase, with the activation energy and activation volume of the sample estimated at (1.25 + 0...

This work presents an intelligent monitoring feasibility on composite insulators. By implanting fiber Bragg grating (FBG) into the composite insulator rod, the intelligence rod structure can online monitor the operating condition of the composite insulator. The transmission matrix is used to get the relationships between the stress strain or the thermal strain and the wavelength drift of in the insulator rod, and based on the results, this work provides the feasibility analysis, the system design and field application.

Streamer is not only the prelude of leader discharge development, but also the important stage of lightning. In order to understand the influence of water droplet sizes on the initiation and growth of discharge, three kinds of mist with different size droplets are applied to study this influence. Based on the measurement of droplet sizes in three mist and directly comparative analyses of the percentages of the discharge path on mist or air in a non-uniform field, at atmospheric pressure, it can be concluded that mist with droplets smaller than 10 µm suppresses the lightning discharge, and has the negative impact on the first step of discharge; mist with droplets greater than 10 µm has the inhibited effect on the starting and growth of positive discharge, but has the contrary effects on negative discharge. These droplets in mist distort the electrostatic field, interact with ions, electrons or photons, and produce corresponding enhancements or decreases in ionization and excitation as the avalanche front encounters them, but the details of different degree alterations on avalanches highly correlate with the droplet sizes.

Set up two-phase mixture, such as air-solid and air-liquid discharge equipments. Carry out some experiments for investigating the development and breakdown of the two-phase mixture discharge under the different voltage, dc and ac and impulse voltage respectively. Found the particle size effect and the polarity effect on the breakdown voltage and the selection of the discharge path. For the smaller size particle, the breakdown voltage is higher than that the middle size particle.

This paper investigates the development, the breakdown process, and the discharge path selection of the lightning discharges while there exist two phase mixtures. 13 kinds of solid-gas mixtures and 3 kinds of liquid-gas mixtures are employed to study effect of two-phase mixtures (TPM) on the selection of the discharge path under lightning impulses. Grain size effects are shown upon these experimental results. When the diameter of solid or liquid grain is less than about 10 mum, the discharge path selects not TPM but air. And the discharge path selects TPM when the diameter is greater than about 100 mum. And the diameter is between about 10 mum and 100 mum, the discharge path selects TPM under negative lightning impulses, but it has a greater selection of air than TPM under positive lightning impulses. Volume fraction and permittivity of solid/liquid can also influence the selection of the discharge path.

A two-phase mixture (TPM) is a mixture of gas and macroparticles of high concentration, and there has been significant interest in many technical applications and natural phenomena concerning two-phase mixture discharges (TPMDs), but until now there has been no widely accepted analysis for the propagation of discharges in TPMs. In this paper, 21 kinds of different dielectric materials are used to investigate the effects on TPMD. The diameters of macroparticles in 21 kinds of TPMs are measured by microscope, laser particle size analyzer, etc, and the volume fractions are measured by a video camera and particle image velocimetry system. Based on a direct comparison of the breakdown voltages and the percentages of the discharge path in TPMs with those in air, this work reveals that whether TPMs promote the discharge development or not depends mainly on the macroparticle sizes. These macroparticles in TPMs distort the electric field, interact with ions, electrons or photons, and produce corresponding enhancements or decreases in ionization and excitation as the streamer front encounters them, but the details of alterations on the discharge development are highly correlated with the macroparticle sizes.