Typically good adhesion properties between the electrode composite and current collectors’ interface should be achieved to deliver the designed power output and cyclability throughout the service period. In order to enhance the surface adhesion properties of the current collectors, surface roughing process, roll pressure, and addition of special binders are commonly employed to maintain the mechanical durability of the electrodes. Such mechanical enhancements have proven beneficial to the cyclability and performance of batteries. [13-15] Besides, in practice, commercial current collectors are often not 100% pure in their metal content. Trace of impurity content may result in continued corrosion of current collectors which can lead to a significant contribution to the Li-ion batteries’ internal resistance of cells, which further results in power and capacity fade.  Therefore, special treatment on current collectors to form protect layer on their surface is conducive to maintain the batteryperformance. Normally, a metal can passivate to enhance its anti-corrosion ability via different ways such as solvent chemisorptions, air-formed layer, alloying additions of transition metals, hydroxide/oxyhydrogxide formation, and a salt film consisting of metal cations and anions from the electrolyte, etc. [17-22] However, to obtain a uniform and effective protect layer on current collectors is still so far challenging.
Spinel-type C-LTO and CNT-LTO nanocomposite particles have been synthesized. Comparative nanostructure analyses (XRD, HRTEM and SAED) and electrochemical testing (charge- discharge, CV and EIS) revealed that the C-LTO particles have excessive carbon coating on the surface, resulting in a high irreversible capacity. The CNT-LTO particles have thinner graphitic layers covering the nanocrystal surface and higher reversible charge–discharge capacity than that of the C- LTO particles at different rates, which is ascribed to the synergistic effect of thinner graphitic layers and CNT interconnection networks of the electrode materials that provide shorter diffusion-paths and faster migration rate of both ions and electrons. This work demonstrates that the CNT-LTO nanocomposite particles have the improved capacitive performance, making it an efficient and highly promising material for use in the development of rechargeable Li-ion cells. The current facile reaction technique represents an effective method for synthesizing Li 4 Ti 5 O 12 anode material for lithiumion
the electrode materials and separation from the substrate [7-10]. In addition, the constant expansion and contraction of silicon lead to the cracking of the solid electrolyte interface (SEI) layer covered on silicon, and this thickening SEI layer as cycle times increasing acts as insulating layer and prevents electron transportation thus decreasing the specific capacity [11-14]. All of the effects mentioned above cause severe capacity fade of silicon-based anode with repeated cycling. It is reported that morphology and particle dimension of silicon in the electrode make a significant impact on the performance of the Si based anode [6, 15-17]. Using the silicon nanoparticles (SiNPs) with a diameter below~150 nm is helpful in easing some of the problems mentioned above such as reducing pulverization of micron-size silicon [18, 19]. However, the use of nanoparticles is only a partial solution to the problems mentioned above. SiNPs shows a bad dispersion property and an electrochemical sintering phenomenon in SiNPs based electrode caused by localized spikes current/voltage in charge/discharge cycle would cause capacity degradation of silicon-based anode [20, 21]. In order to avoid these problems, different carbon coating forms on SiNPs are reported and demonstrated improved performance such as discharge capacity, rate capability and cycle life [3, 4, 22-25]. To further improving cycle property of silicon-based anode, second phase component can be added to buffer the volume fluctuation during the whole discharge/charge cycle. Carbon nanotube (CNT) shows high electrical conductivity, chemical stability and mechanical flexibility. Si coating on CNT (Si@CNT) is an effective way to exploit the advantages of both SiNPs and CNT. In the Si@CNT system, CNT provides an ideal conducting scaffold for holding SiNPs while the whole framework is easy to accommodate cyclic volume fluctuations [26, 27]. It is the easiest thing to implement that CNT was added as an additive to develop conductive pathways in Si- based anode [28, 29]. In fact, it is difficult to disperse Si nanoparticles into CNTs to fabricate well linked Si@CNT composites. Chemical vapor deposition is an effective way to directly deposit SiNPs on the surface of CNT but the high cost and low yield of this method restricted their industrialized applications [30-33]. Also, the method through forming peptide coupling between surface amine-modified SiNPs and carboxyl-functionalized CNTs was used to prepare Si-CNT composite [34, 35]. Fabricating Si coated CNTs composite was also reported via Magnestiothermic reduction on SiO 2 coated CNTs composites
Irrespective of the exact choice of battery chemistry, there are important design parameters which can be varied within the manufacturing process to improve cell performance. These include electrode thickness, particle size, porosity, electrode surface area, geometry and the dimensions of the current collectors  . Newman and co-workers [8–10] applied new math- ematical approaches to optimise the design variables of a lithiumionbattery. They developed a simpliﬁed battery model to facilitate the mathematical formulation of the problem and to allow the optimisation of the porosity and electrode thick- ness  . Discharge time and cell capacity were found to be the most signiﬁcant factors affecting their ﬁnal design. Further, they also investigated the inﬂuence of different particle size distributions on the operation of porous electrodes  . Their research continued as they developed a full cell model to evaluate the ohmic related energy loss of the solid electrolyte interface (SEI) layer. Their model was used to optimise the design of a graphite–iron phosphate cell  . In addition, the authors continued to develop a comparable model to optimise and evaluate the performances of both graphite and titanate negative electrodes  .
The global energy shortage and environmental issues have led to rapidly increasing requirements for highly efficient sources of clean energy, such as solar, wind power and biomass . Therefore, the development of novel energy storage and conversion systems is urgently required for efficient utilization of renewable energy . Lithium-ion batteries (LIBs) are one of the best developed and commercialized battery technologies for portable electronic devices such as laptops, mobile phones, medical devices, and electric vehicles. They possess various outstanding features, including high energy density, no memory effect, low maintenance and low self-discharge [3, 4]. At present, the energy density of commercial LIBs is less than 200 Wh kg −1 , which is insufficient for the growing energy demands of emerging technologies. One of the primary methods to achieve higher energy densities is to explore new electrodes materials with high reversible capacities and excellent stability. The typical cathode and anodes materials used in modern LIBs are lithium cobalt oxide (LiCoO 2 ) and graphite,
However, the composite electrodes described above remain far from optimised as LIB electrodes. Although such approaches generally result in good capacity and improved stability, the rate capability is still not as good as had been hoped. In addition, many of the processing techniques used are not straightforward and may not be scalable. Perhaps most importantly, comprehensive compositional studies have not been performed and a detailed understanding of the relationship between nano-conductor content and the electrical or mechanical properties of the electrode is still missing. In fact, even the dependence of electrode capacity on nano- conductor content has not been studied in any depth. We believe that the full optimisation of LIB electrodes based on 2D materials is impossible until such detailed studies have been performed. Moreover, such a study could result in deep insights into the operation of composite electrodes. In addition, any results obtained could probably be transferred to other electrode materials which suffer from poor electrical and mechanical performance.
More attention is being given to improving many characteristics such as wetness, water expulsion, pollution, soil release, printability, printability and other finishing processes for textile fibers and fabrics by plasma technology . By controlling its variables, such as the nature of the gas, it can improve the discharge strength, pressure and exposure time, and a large variety of surfaceproperties . Plasma technology applied to textile manufacturing has evolved considerably over the past decade, due to its potential benefits in environmental and energy conservation, in the development of high-performance materials for the global market . The surfaceproperties of natural or synthetic fibers or filaments can be modified using plasma treatment. This can lead to processes such as polymerization, grafting, cross-linking, etc., with concomitant effects on wetting, wicking, dyeing, printing, surface adhesion, electrical conductivity and other characteristics of interest to the textile industry .
Lithium-ion batteries are the most suitable in existing technology for electric vehicles because they can deliver high output because of having capability to store high power per unit of battery mass, allowing them to be lighter and smaller than other rechargeable batteries. These features also explain why lithium-ion batteries are already widely used for consumer electro nics such as cell phones, laptop computers, digital cameras/video cameras, and portable audio/game players. Other advantages of lithium-ion batteries compared to lead acid and nickel metal hydride batteries include high-energy efficiency, no memory effects, no self- discharging and a relatively long cycle life. The electric scooter uses battery having capacity of 48V 20Ah capacity.
selected as follows (tree - square - rectangle - triangle - circle - oval - star - hexagons) and after the work of analysis on the city of Cairo proved the results valid hypothesis that the form taken from nature leads to better performance in terms of heat and humidity From these results Make sure the design
Electrochemical Measurements: the working electrodes were prepared by mixing active materials, carbon black, and PVDF (in a weight ratio of 70:20:10). The mixture slurry was uniformly pasted on the Al foil with a blade. The slurry-coated Al foil was dried at 120 °C in a vacuum oven overnight, followed by punching into circular electrodes with a diameter of 12 mm. The thickness of the cathode without Al foil is about 35 μm, which is more thicker than most of V2O5-based cathodes. Electrochemical measurements were carried out using coin-type cells (CR2032). Lithium plates were used as the counter electrode, and a 1 M solution of LiPF 6 in ethylene carbon (EC)/dimethyl
The ever-increasing energy demand are primary driving forces for the exploitation of environmental friendly renewable energy storage materials. Among different energy store apparatus, lithium-ion batteries (LIBs) have displayed superior electrochemical performances in terms of high battery voltage, long recycle life, low self-discharge, no memory effects, high energy ratio power and energy densities, and environmental friendliness. The currently commercialized graphite anode has some interesting performance, for example lower working voltages versus Li, long recycle life, and lower cost. However, its main disadvantage is its low theoretical specific capacity of 372 mAh g -1 ,
doping and nano-sized rod-like micrograph. Apart from that, the addition of aluminum ions and silicon ions is able to impose a positive effect on the reduction of the lithium-ion diffusivity [24, 41], and the one-dimensional nanorod-like structure is quite conducive to the improvement of electronic conductivity . As far as the LiMn 1.92 Al 0.04 Si 0.04 O 4 nanorods are concerned, the initial charge-transfer resistance is
interfacial storage was excluded in the calculation of theoretical capacities . Based on the ratios of theoretical and actual discharge capacities, it can be concluded that both anode materials perform similarly. The 10-20% extra capacities above the theoretical values should stem from charge loss to SEI formation as well as possible interfacial lithium storage. Despite similar discharge behavior, a very noticeable difference is observed in charge (delithiation) capacities. The LiNMC has a 1 st cycle charge capacity of 793 mAh/g while NMC can only achieve 605 mAh/g (delithiation capacities of similar materials from literature are provided for comparison in Table 3 in supporting information). These numbers correspond to about 77% and 61% coulombic efficiencies for LiNMC and NMC anode materials, respectively (Figure S1). These results were confirmed with sister cells. Given that both anode electrodes had the same formulation, such a disparity between two anode materials with the same metal composition might be explained by the difference in average metal nanoparticle diameters in their fully lithiated states as well as the availability of extra Li 2 O matrix in LiNMC.
Electrochemical performances of the samples were mea- sured using CR2025 coin-type cells assembled in a dry argon-filled glove box. To fabricate the working elec- trode, a slurry consisting of 60 wt.% active materials, 10 wt.% acetylene black, and 30 wt.% polyvinylidene fluoride (PVDF) dissolved in N-methyl pyrrolidinone was casted on a copper foil and dried at 80°C under vacuum for 5 h. Lithium sheet was served as counter and reference elec- trode, while a Celgard 2320 membrane (Shenzhen, China) was employed as a separator. The electrolyte was a solu- tion of 1 M LiPF 6 in ethylene carbonate (EC)-1,2-dimethyl
Abstract A power storage system using spherical Si solar cells, lithium-ionbattery and a direct current-alternating current (DC-AC) converter was constructed. A small and light inverter system was developed by combining a maximum power point tracking charge controller, direct current-direct current (DC-DC) converter, and DC-AC converter. Performance evaluation of the inverter system with SiC field-effect transistors (FET) and Schottky barrier diodes (SBD) was carried out, and the DC-AC conversion efficiencies and their stability of the inverter were improved compared with those of the ordinary Si-FET/SBD based inverter.
present results followed exactly the same trend since the solid content of the slurry was very high (>50%). Un- fortunately, the rheometer used in the current study could not sensibly obtain the stress/strain response at very low strain or time, and therefore not possible to observe the elastic solid region at very low strain. Nevertheless, following the mechanism proposed by Uhlherr et al. , the yield stress of the cathode sample obtained from the Rushton and the 3D mixers was around 1 Pa, and from the ball mill was around 25 Pa. Hence, there was a difference in the internal structure of the slurry when subjected to low strain oscillation flow. At high strain, all three samples behaved like a viscous liquid and the curves for the ball mill and the 3D mixers were closer to each other.
supposed to be 3.0 V/0 V , but a new testing voltage range was applied in this work. Theoretically, a high charge end voltage might result in structural distortion of electrode material, directly causing the decrease of capacity. Besides, it has been reported that capacity of transition metal selenide for lithiumionbattery could die dramatically. Thus it is commonly composited with carbon material. And, carbon/Li battery was usually cycled between 2.0 V and 0 V. As a result, a series of tests were applied to figure out the most appropriate voltage range in this work.
For over a century, petroleum-derived fuels have been the first choice as an energy source for transportation, and accounted for more than 71.4% of U.S. petroleum use in 2009 . Although the petroleum-based fuel energy resource is convenient and technically mature, researchers started looking for alternative energy sources such as batteries due to the shortage of petroleum and because burning fossil fuels has become an environmental issue. It is reported that 98% of carbon dioxide emissions come from petroleum fuels . Since carbon dioxide accounts for the largest share of greenhouse gases, to meet the stated goal of reducing total U.S. greenhouse gas emissions to 83% below 2005 levels by 2050, an alternative energy storage system is required. One of the most promising energy storage solutions for future automotive technology is the rechargeable battery. Compared with other resources such as flywheels, capacitors, biofuel, solar cells, and fuel cells, rechargeable batteries are more portable and provide quick energy storage and release [3-5]. Moreover, it is more difficult to use these other resources globally than it is to use rechargeable batteries, due to the operating environment limitations for these other energy sources . Compared with capacitors, rechargeable batteries have lower self-discharge rates [3, 5], thus holding their charge for longer periods of time. Therefore, to best serve as a future automotive technology, rechargeable batteries should have both high energy and power densities , the ability to output high current for a long period of time, and to be fully charged quickly. The durability and environmental friendliness of rechargeable batteries is also very important. They should work for several years safely under different climatic conditions, and even if involved in an unfortunate car collision.
The in vitro dissolution data showed that 66-89% of the drug was dissolved in 90 minutes, and there was increase in the dissolution of drug in formulations compared to the pure form. The batch 1:2 accounted for maximum yield and in turn resulted as the batch that gave a % cumulative release (% CR) of 89.08% as compared to the pure drug which gave 40.436% release (Fig.7). Formation of partially amorphous olmesartan during crystallization as seen from could also be a minor factor involved in dissolution enhancement. The successfully formulated solid dispersion led to a better solubility profile of the drug in its amorphous form when compared to its pure form. The saturation solubility of Olmesartan and porous starch showed an 84-fold enhancement over pure drug. The DSC pattern of the drug and formulation confirmed that the crystalline nature of the drug remained changed into amorphous form. The enhanced dissolution profile of drug attributed to the increased wettability of the drug in the formulation and formation of a hydrophilic surface. In conclusion, it can be stated that solid dispersion technology is a promising strategy to increase the solubility and dissolution rate of poorly soluble drugs.
about 1000 mAh g -1 . After five cycling the discharge specific capacity fell to about 650~700 mAh g -1 . In fact, after 15 th cycling the discharge specific capacity continue fell down (not shown in Fig. 3). The discharge specific capacity attenuation might cause by the electrode pulverization and loss of interparticle contact or the particle with copper foil collector due to large volume expansion/contraction during repeated charging-discharging processes and severe particle aggregation. As reported for other metal oxide anode, Li storage in SnO 2 is primarily based on multiple