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Li-ion batteries (LiB) play nowadays a major role in several technological fields. In addition to enhanced high capacity and long cyclability, some other issues regarding safety, materials sustainability, and low cost remain unsolved. Tin oxide (SnO2) presents several of those advantages as an anode material; however, some aspects still require to be investigated such as capacity fading over cycles. Herein, tin oxide nanoparticle-based anodes have been tested, showing high capacities and a significant cyclability over more than 150 cycles. A complementary strategy introducing doping elements such as Li and Ni during the synthesis by hydrolysis has been also evaluated versus the use of undoped materials, in order to assess the dependence on SnO2 quality and properties of battery performance. Diverse aspects such as the Sn charge state in the synthesized nanoparticles, the variable incorporation of dopants, and the structure of defects have been considered in the understanding of the obtained capacity.

Lithium rich layered metal oxide is a high energy density cathode material for new generation lithium-ion batteries (LIBs). This material has Li [Li1/3Mn2/3]O2 and LiMO2 (M: Ni, Co, Mn, Al etc.) structure and exhibit higher irreversible capacity and cycle life than conventional cathode materials. In this study, the stoichiometry of metals in the lithium rich cathode material formulation was investigated by changing Mn, Ni and Co ratios. Li1.2Mn0.49+xCo0.2-2xNi0.2-2xAl0.02O2 (x = 0, 0.01, 0.02, 0.03). formulation was used and the prepared lithium rich cathode active powders were structurally characterized by XRD, ICP and NAA. Li-rich cathodes were tested by electrochemical methods, too.

Self-healing is the capability of materials to repair themselves after damage has occurred, usually by interaction between molecules or chains. Physical and chemical processes are applied for the preparation of self-healing systems. There are different approaches for these systems such as heterogeneous systems, shape memory effects, hydrogen bonding or covalent-bond interaction, diffusion and flow dynamics. Self-healing mechanisms can occur in particular by heat and light exposure or by reconnection without direct effect. The applications of these systems display an increasing trend in both R&D and industry sectors. Moreover, self-healing systems and their energy storage applications are currently getting great importance. This review aims to provide general information on recent developments in self-healing materials and their energy applications in view of the critical importance of self-healing systems for lithium-ion batteries (LIBs). In the first part of the review, an introduction about self-healing mechanisms and design strategies of self-healing materials is given. Then, selected important healing materials in the literature for the anodes of LIBs are mentioned in the second part. The results and future perspectives are stated in the conclusion section.

Self-healing is the capability of materials to repair themselves after the damage has occurred, usually through the interaction between molecules or chains. Physical and chemical processes are applied for the preparation of self-healing systems. There are different approaches for these systems, such as heterogeneous systems, shape memory effects, hydrogen bonding or covalent–bond interaction, diffusion, and flow dynamics. Self-healing mechanisms can occur in particular through heat and light exposure or through reconnection without a direct effect. The applications of these systems display an increasing trend in both the R&D and industry sectors. Moreover, self-healing systems and their energy storage applications are currently gaining great importance. This review aims to provide general information on recent developments in self-healing materials and their battery applications given the critical importance of self-healing systems for lithium-ion batteries (LIBs). In the first part of the review, an introduction about self-healing mechanisms and design strategies for self-healing materials is given. Then, selected important healing materials in the literature for the anodes of LIBs are mentioned in the second part. The results and future perspectives are stated in the conclusion section.

A new design for conjugation and crosslinking combined with a conjugated polymer and its application for high capacity Li-ion battery are demonstrated. Polyfluorene (PF), poly(phenylene) (PP), with lateral substituents, namely carboxylic acids, as a potential building block for conjugation was synthesized and characterized. The synthesis was achieved through Suzuki polycondensation reaction in the presence of Pd(PPh3)4 catalyst by using dibromo benzoic acid in conjunction with dioctylfluorene-diboronic acid bis(1,3-propanediol) ester. Thermal chemical cross-linking between carboxylic acid in the polymer backbone and free hydroxyl groups in poly(vinyl alcohol) (PVA) has been performed in the presence of Si. This approach enables a polymer binder with multi-functionality providing a high electronic conductivity and good cycling stability. Overall, we report on a Si-anode with capacity of 1932 mAh/g at C/3, demonstrating the improvement of the electrode using gel polymer binder.

The emergence and the continuous rise of smart technologies require to emergently meet their ever-increasing energy demand. Improving the commercial lithium-ion batteries (LIB) by using silicon-which has a distinct energy storage capacity-might be a promising solution. However, solving Sirelated problems, such as gross volume variation and low electrical conduction, is indispensable. Preparing different Si nanostructures having certain internal voids, and adding some conductive materials, are two smart approaches largely used to mitigate the volume expansion and to enhance the electrons transport of LIB anodes. Still, their raw materials and their preparation methods are generally costly, which limits their feasibility for commercial scalability. In this study, we synthesized a coral-like nanoporous Si/rGO composite, starting from cheap raw materials (graphite and Al-Si powders), and using simple methods which do not need any high temperatures or sophisticated equipment. The preparation steps were also reduced, as the reactions of Al-etching and GO reduction concurrently occurred. The LIB half-cells made on this composite were further improved by incorporating other carbon nanomaterials which had a synergistic effect on both cycling and rate performances: a reversible capacity of 1080 mAh g(-1) at 0.2 A g(-1) after 250 cycles; and similar to 1710,1300,1030 - and 840 mAh g(-1) at a rate of 1, 2, 3, and 4 A g(-1) respectively, have been achieved. Testing a full battery with an LCO cathode has also given a promising result: a reversible capacity of similar to 54 mAh g(-1) at 36 mA g(-1) after 25 cycles has been obtained. (C) 2020 Elsevier Ltd. All rights reserved.

Lithium rich (Li-rich) transition metal oxide cathodes are considered to be among the most promising intercalation cathode materials used for lithium-ion batteries (LIBs) with their high energy density above 900 Wh/kg. Li1.252Mn0.557Ni0.123Co0.126Al0.0142O2 layered Li-rich nickel manganese cobalt (NMC) cathode material was synthesized by sol-gel method. This study aims to reveal the superiority of Li-rich cathode material over existing commercial cathodes. The stoichiometric ratio of Li-rich cathode material was confirmed by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS), portable X-ray Fluorescence (pXRF) and Instrumented Neutron Activation Analysis (INAA). Structural and morphological characterization of Li-rich NMC material was examined with X-ray diffraction (XRD) and Scanning Electron Microscopy-Emission with Energy Dispersive Spectroscopy (SEM-EDS). Electrochemical performances of Li-rich NMC and commercial NMC111 cathode materials in coin cell at C/10, C/5 and 1C were investigated. The discharge capacity of Li-rich NMC and NMC111 was found to be 160, 156, 96 mAhg−1 and 153, 120, 72 mAhg−1 at C/10, C/5, 1C, respectively.

In this study, as a novel design with the collaboration of a fluorene and sulfide-based copolymer for Li-ion battery application is presented. Polyfluorene-co-polydisulfide is prepared with desired functional groups to yield a conductivity and good adhesion. These critical and important features are performed by preparing polymers with proper functional groups. The preparation process is accomplished via Suzuki coupling process under Pd catalyst by combining separately synthesized 4,4 '-dibromodiphenyl disulfide in combination with 9,9-dioctylfluorene-2,7-bis(trimethylborate). The fully obtained capacity of the silicon particles, that is, at C/10 with the capacity of 1250 mAh g(-1) after the 500th cycle, approves the good performance by preserving capacity stability till 600th cycles. The designed and synthesized polymer binder with different functionalities and carbon nanotube additive show better characteristics such as conductivity, high polarity, and binding adhesion. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48303.

Silicon is a promising anode active material for lithium ion batteries due to improvements to overcome the volume expansion problem and preserve the electrode structural integrity during the lithiation and delithiation processes. Significant studies have been performed to overcome this problem and make silicon available for commercial applications. In this study, we developed a facile and functional method to demonstrate the possibility of widespread usage of silicon anode. Here, two methods were investigated; neutralization of poly(acrylic) acid (PAA) and calendering process during electrode production. PAA without neutralization is commonly used in silicon based anodes. Calendering is a typical process for cathode preparation. However, it is not generally utilized for making silicon anodes. This study aims to show the effect of PAA neutralization and anode calendering on the electrochemical performance of cells in comparison to anodes prepared by conventional processes. Furthermore, a high mass loading is a critical step for the use of Si anode commercially. The electrode was successfully loaded in this study as 1 mg/cm2. Electrochemical performance measurements showed that 1370 mAh/g specific capacity was achieved after neutralization of PAA and calendering of the electrode at the 100th cycle. Meanwhile, the calendered electrode prepared with PAA polymer showed a specific capacity of 511 mAh/g after 100 cycles. Traditionally, graphite is used as anode material in commercial batteries and theoretical specific capacity is 372 mAh/g. Our observations with quite high specific capacity achieved by the process applied in this study show an important promise for the use of silicon based anode materials in the future utilization of Li ion batteries.

Hybrid composites based on inorganic nanomaterials embedded into a polymer matrix have were synthesized and characterized. Oxide semiconductor nanoparticles (SnO, SnO2, TiO2, Ga2O3, and NiO) and Si nanoparticles were employed as inorganic counterparts in the hybrid composite, while a conductive polymer (PEDOT:PSS) with diverse additives was used as the organic matrix. The composites were spin-coated on Si or glass substrates. The potential use of these materials in photovoltaic devices to improve Si surface passivation behavior was investigated. Besides, the use of the nanoparticles as active materials for anodes in Li-ion batteries was evaluated. Some other aspects, such as the durability and stability of these materials, were also assessed.

New material compositions with new electrode designs have the serious potential to improve the energy per weight and volume at reduced cost for lithium ion batteries. Herein, the advantage and disadvantage of electrode materials for LIBs were investigated in both half and full cells. It was found high capacity materials like silicon anode and Li-rich cathode provide higher specific capacity in mAh/g. In full cell configuration Graphite/Li-rich cathode had 92mAh/g specific capacity after 100 cycles at C/2.

The performance of a lithium-ion cell depends on the form of the solid−electrolyte interphase (SEI) layers which is composed on the electrode surface. Here, we present a components of the electrolyte solutions for LIBs, namely, fluoroethylene carbonate (FEC) and vinyl carbonate (VC). We discuss the effect of 2, 5 and 10% FEC and VC-based electrolyte solutions in LiPF6 in EC:DEC to understand the SEI layer formed on Si anode., Lityum iyon hücrelerin performansı, elektrot yüzeyinde oluşan Katı Elektrolit Arayüzey (KEY)’in yapısına bağlıdır. Bu çalışmada, elektrolit çözeltisinin bileşeni olarak FEC (floroetilen karbonat) ve VC (vinil karbonat)kullandık. %2, %5 ve %10 FEC ve VC katkılandırılmış EC:DEC içinde LiPF6 elektolitinin Si anot üzerinde oluşan KEY tabakasına etkileri tartışılmıştır.

Use of hydrogen in spark ignition engines as supplementary fuel can be preferred due to improved combustion characteristics and emission advantages. However, hydrogen storage and production difficulties under the hood limit the use of it in internal combustion engines (ICEs). In this study, a different approach was used to overcome these difficulties. Hydrogen and oxygen gas mixture was produced by electrolyser and consumed simultaneously to eliminate the necessity of a storage device. Firstly, a practical alkaline water electrolyser was designed and manufactured to produce hydrogen from water to be subsequently used in ICE as a supplementary fuel. In order to optimize electrolyser, the parameters of gap between plates, concentration of solution and voltage were kept under control. Then, H2/O2 gas mixture used as secondary fuel in SI engine was generated by electrolyser on optimized operating conditions. 0 and 20 l/min H2/O2 mixture as supplementary fuel was introduced into intake manifold of engine using gas injectors where 0 l/min refers to without hydrogen case and 20 l/min with hydrogen case. According to the results, the brake power and brake thermal efficiency were increased by means of hydrogen addition. Besides, total hydrocarbon and carbon monoxide emissions decreased, whereas the dramatic increase of nitrogen oxides emissions couldn't be prevented during the experimental work.

Here we describe a class of electric-conducting polymers that conduct electrons via the side chain π-π stacking. These polymers can be designed and synthesized with different chemical moieties to perform different functions, extremely suitable as a conductive polymer binder for lithium battery electrodes. A class of methacrylate polymers based on a polycyclic aromatic hydrocarbon side moiety, pyrene, was synthesized and applied as an electrode binder to fabricate a silicon (Si) electrode. The electron mobilities for PPy and PPyE are characterized as 1.9 × 10(-4) and 8.5 × 10(-4) cm(2) V(-1) s(-1), respectively. These electric conductive polymeric binders can maintain the electrode mechanical integrity and Si interface stability over a thousand cycles of charge and discharge. The as-assembled batteries exhibit a high capacity and excellent rate performance due to the self-assembled solid-state nanostructures of the conductive polymer binders. These pyrene-based methacrylate binders also enhance the stability of the solid electrolyte interphase (SEI) of a Si electrode over long-term cycling. The physical properties of this polymer are further tailored by incorporating ethylene oxide moieties at the side chains to enhance the adhesion and adjust swelling to improve the stability of the high loading Si electrode.

High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated in the reduction of thickness and porosity, as well as the increase of density. SiO particle size remains unchanged after calendering. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and overcalendered electrode. The calendered electrode has a high-density of ∼1.2 g/cm(3). A high loading electrode with an areal capacity of ∼3.5 mAh/cm(2) at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendering method.

We investigated the use of polymerized vinylene carbonate (polyVC) as a binder for graphite anodes in lithium-ion cells. It functions not only of a traditional binder, but also plays an important role in surface stabilization of graphite in propylene carbonate (PC)-based electrolytes. In an electrolyte with PC content as high as 30 wt%, the polyVC binder enhanced battery performance, with a reversible capacity of ∼170 mAh g −1 at a delithiation rate of 1 C, whereas a comparable graphite cell fabricated with a polyvinylidene fluoride (PVDF) binder failed to cycle.

The aim of this study was to synthesize the carbon-based nanomaterials and determine their hydrogen storage capacities. Carbon nanotubes (CNTs) were first synthesized by chemical vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide (MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O) solution. The synthesis parameters were selected as the synthesis temperatures of 500 and 800°C, the iron content in the precursor of 5% and the synthesis time of 30 minutes. The synthesized material was purified by using HCl at 75°C for 15 hours. After synthesis of CNTs, the polyaniline-doped H3BO3 and BF3 and composites were prepared by coagulation method. The synthesized CNTs and composites were characterized by transmission electron microscopy, FT-IR spectroscopy, Raman spectroscopy and thermogravimetric analyzer. The BET specific surface areas were obtained from the nitrogen adsorption isotherms at -196°C. The hydrogen storage capacities of these carbonaceous materials were measured using volumetric m...

© 2016 American Chemical Society. Control over porous electrode microstructure is critical for the continued improvement of electrochemical performance of lithium ion batteries. This paper describes a convenient and economical method for controlling electrode porosity, thereby enhancing material loading and stabilizing the cycling performance. Sacrificial NaCl is added to a Si-based electrode, which demonstrates an areal capacity of ∼4 mAh/cm2at a C/10 rate (0.51 mA/cm2) and an areal capacity of 3 mAh/cm2at a C/3 rate (1.7 mA/cm2), one of the highest material loadings reported for a Si-based anode at such a high cycling rate. X-ray microtomography confirmed the improved porous architecture of the SiO electrode with NaCl. The method developed here is expected to be compatible with the state-of-the-art lithium ion battery industrial fabrication processes and therefore holds great promise as a practical technique for boosting the electrochemical performance of lithium ion batteries without changing material systems.

Hydrogen is considered to be a clean energy carrier. However, the most serious barrier to potential uses is the development of feasible hydrogen storage systems. The discovery of high hydrogen storage capacity of carbon nanotubes (CNTs) makes up alternatives for hydrogen storage systems. In this study, the hydrogen adsorption on carbon nanotubes was investigated. CNTs were firstly synthesized by chemical vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide (MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O) solution. The synthesis parameters were selected as: the synthesis temperature of 800 °C, the iron content in the precursor of 5% and the synthesis time of 30 min. The liquid phase oxidation method was applied for the purification of the synthesized CNT materials. Three different chemicals—3 M HNO3, H2SO4, and HCl–were used in the removal of the metal catalysts from the synthesized CNT material to investigate the possible effects of each acid solution to the purification step. Purification of the synthesized CNT material was carried out under the conditions of 75 °C for 15 h. A 30% H2O2:3 M HCl (1:1 v%) solution was also used in the purification step to remove both the metal catalysts and the amorphous carbon. The purification using this solution was performed at 75 °C for 8 h. The hydrogen storage capacities of the purified materials were measured using volumetric method. It was found that the hydrogen adsorption capacities of these materials were changed in the range of 0.60–4.86 wt% at the liquid nitrogen temperature and gas pressure up to 100 bar.

Based Materials N. Yuca, N. Karatepea,∗, F. Yakuphano§lu and Y.H. Gursel Energy Institute, Istanbul Technical University, Istanbul 34469, Turkey Physics Department, Firat University, Elazig 23169, Turkey Chemical Department, Istanbul Technical University, Istanbul 34469, Turkey In this study, carbon nanotubes were synthesized at temperatures of 500 ◦C and 800 ◦C by the uidized-bed chemical vapor deposition method. The synthesized material was puri ed by using 3 M HCl at 75 ◦C, 15 h. After synthesis and puri cation, the polyaniline-doped H3BO3 and BF3 and composites were prepared by coagulation method. Transmission electron microscope and Fourier transform infrared spectroscopy were used to characterize the carbon nanotubes and their composites. Thermal stabilities were measured by thermogravimetry and di erential scanning calorimetry instruments. The thermogravimetry and derivative thermogravimetry curves indicated that the thermal stability of polyaniline-doped H3BO3 and BF3 increased with carbon nanotube doping. The electrical properties of carbon nanotubes and their composites were also determined. The obtained electrical conductivity values of the nanocomposites including the polyaniline-doped H3BO3 and BF3 were typical for organic semiconductor materials. It can be evaluated that the electrical properties of the polyaniline based polymers can be controlled by carbon nanotube doping.

© 2014 American Chemical Society. The mechanical failure at the electrode interfaces (laminate/current collector and binder/particle interfaces) leads to particle isolation and delamination, which has been regarded as one of the main reasons for the capacity decay and cell failure of lithium-ion batteries (LIBs). Polymer binder provides the key function for a good interface property and for maintaining the electrode integrity of LIBs. Triethylene glycol monomethyl ether (TEG) moieties were incorporated into polymethacrylic acid (PMAA) to different extents at the molecular level. Microscratch tests of the graphite electrodes based on these binders indicate that the electrode is more flexible with 5 or 10% TEG in the polymer binders. Crack generation is inhibited by the flexible TEG-containing binder, compared to that of the unmodified PMAA-based electrode, leading to the better cycling performance of the flexible electrode. With a 10% TEG moiety in the binder, the graphite half-cell reaches a reversible capacity of >270 mAh/g at the 1C rate, compared to a value of ~190 mAh/g for the unmodified PMAA binder.

Carbon nanotubes (CNTs) with their high mechanical, electrical, thermal and chemical properties are regarded as promising materials for many different potential applications. Chemical vapor deposition (CVD) is a common method for CNT synthesis especially for mass production. There are important parameters (synthesis temperature, catalyst and calcination conditions, substrate, carbon source, synthesis time, H 2 reduction, etc.) affecting the structure, morphology and the amount of the CNT synthesis. In this study, CNTs were synthesized by CVD of acetylene (C 2 H 2 ) on magnesium oxide (MgO) powder substrate impregnated by iron nitrate (Fe (NO 3 ) 3 •9H 2 O) solution. The synthesis conditions were as follows: at catalyst calcination temperatures of 400 and 550°C, calcination time of 0, 15, 30 and 45 min, hydrogen concentrations of 0, 50 and 100 % vol, synthesis temperature of 800°C and synthesis time of 30 minutes. The synthesized materials were characterized by thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), X ray diffraction (XRD) and Raman spectroscopy. Effects of H 2 reduction on catalyst calcination and CNT synthesis were investigated.

Transition-metal catalysts, fullerenes, graphitic carbon, amorphous carbon, and graphite flakes are the main impurities in carbon nanotubes. In this study, we demonstrate an easy and optimum method of cleaning SWCNTs and evaluating their purity. The purification method, which employed oxidative heat treatment followed by 6M HNO 3 , H 2 SO 4 , HNO 3 :H 2 SO 4 and HCl acid reflux for 6h at 120°C and microwave digestion with 1.5M HNO 3 for 0.5h at 210°C which was straightforward, inexpensive, and fairly effective. The purified materials were characterized by thermogravimetric analysis and nuclear techniques such as INAA, XRF and XRD.

Having remarkable characteristics, carbon nanotubes (CNTs) have attracted a lot of interest. Their mechanical, electrical, thermal and chemical properties make CNTs suitable for several applications such as electronic devices, hydrogen storage, textile, drug delivery etc. CNTs have been synthesized by various methods, such as arc discharge, laser ablation and catalytic chemical vapor deposition (CCVD). In comparison with the other techniques, CCVD is widely used as it offers a promising route for mass production. High capability of decomposing hydrocarbon formation is desired for the selected catalysts. Therefore, transition metals which are in the nanometer scale are the most effective catalysts. The common transition metals that are being used are Fe, Co, Ni and their binary alloys. The impregnation of the catalysts over the support material has a crucial importance for the CNT production. In this study, the influence of the support materials on the catalytic activity of metals was investigated. CNTs have been synthesized over alumina (Al 2 O 3 ), silica (SiO 2 ) and magnesium oxide (MgO) supported Fe, Co, Fe-Co catalysts. Catalyst – support material combinations have been investigated and optimum values for each were compared. Single walled carbon nanotubes (SWCNTs) were produced at 800°C. The duration of synthesis was 30 minutes for all support materials. The synthesized materials were characterized by thermal gravimetric analysis (TGA), Raman spectroscopy and transmission electron microscopy.

The early development on rechargeable lithium battery began with lithium (Li) metal and Sony put into the market the first lithium ion batteries in 1991. Since that date the graphite has been used as commercial anode with the practiable capacity of 250 mAh/g and it has been yet reached the 290 mAh/g in 2015 [1]. In the development of high capacity anode materials for lithium ion batteries, silicon is apparently very promising as anode material due to its high theoretical capacity ~4200 mAh/g. However, the huge volume change (~300%) occurs during the cycling and it results breakdown of the conductive network of the composite electrode. This causes the electrical contact problem between conductive agent and the current collector, resulting low Coulombic efficiency and poor capacity retention for silicon-based lithium ion batteries (LIBs). Polypyrene (Ppr) polymer has much concern recently not only the conductivity and other electrical properties but also thermal stability and mechanical properties. In this study, the aim is to enhance the conductivity of Si electrode which is crucial for charge-discharge rate of a battery. The high conductivity provides fast charge-discharge and that is very important for consumer electronics and electric vehicle applications. For this purpose, the conductive Ppr was synthesized through the free-radical polymerization of the acrylate backbone in the presence of an initiator. It was used as a conductive polymer for silicon anode in LIBs. The conductivity of anode was also studied with different carbonecous additives (carbon black, super p and carbon nanotube). The cells were fabricated as half and full cell. Li was used as the counter electrode for half-cell and NCA was used as the cathode for full cell. Table 1. Experimental results for the conductivity study of Si anode Experiment No Composition Ratio Active Material Binder Conductive additive 1 90:10 Si Ppr - 2 85:15 Si Ppr - 3 85:10:5 Si Ppr CB 4 85:10:5 Si Ppr SP 5 85:10:5 Si Ppr CNT 6 85:10:5 Si PVDF CB

The growing energy use of modern societies has created a major need for better approaches to not only the production and management of energy, but also its storage. As they have high energy density and cyclability lithium-ion batteries (LIBs) serve currently as the secondary rechargeable battery systems for portable devices and electric vehicles (EVs). However, there are weight and volume constraint for the LIB systems especially for vehicle applications due to the limited space and energy consumption. Energy density limitation of LIBs is the main drawback for successful commercialization of EVs because of its direct effect on the vehicle's driving range, so enhancing the negative and positive electrodes by increasing their capacities and operating voltage is the best approach to improve the electro chemical performance of LIBs. Lithium rich layered oxides, which are solid solutions between layered Li[Li1/3Mn2/3]O2 (commonly designated as Li2MnO3) and layered Li[Mn1-y-zNiyCoz]O2, have been comprehensively studied as next generation cathode materials as they show much higher specific capacity (∼250 mAh/g) and operating voltage (>4.5) compared to the commercial cathodes. One of the defining characteristics of lithium-rich layered oxides (LLOs) is that they exhibit a unique first charge profile. The first charge profile can be divided into two regions, the sloping (below 4.5 V) and plateau regions (above 4.5 V), depending on the mechanism of oxidation during lithium-ion extraction. However, increase in voltage results O2 release from Li2MnO3 structure in the form of LiO2. This mechanism is one of the crucial drawbacks for Li-rich cathodes that results in huge capacity fade during cycles because of the structural change that occurs in Li2MnO3 phase (at high voltages). Therefore, in this study, different upper voltage limits (4.2-4.8 V) are investigated for Li[Li0,2Mn0,54Ni0,13Co13]O2 in order to analyze and optimize the capacity retention.

Rechargeable lithium ion batteries (LIB) have been vastly used in portable devices like cellular phones, laptops, tablets and also in electric vehicles because of their relatively high energy density, good power performance and cycle life. Carbonaceous negative electrode materials, especially graphitic carbons are conventionally used as anode materials at LIBs due to their good cycle-ability and low stable discharge voltage plateau. However, graphite has a low Li atomic density at full Li capacity in carbon intercalation compound (LiC6) which leads to lower theoretical capacity (372 mAh/g). Therefore, different types of anode active materials have been investigated as an alternative to graphite in order to achieve higher capacities. Among them, silicon (Si) is one of the most promising candidate as an anode active material because of its high theoretical capacity (more than 3500 mAh/g at room temperature) and low average discharge potential (∼0.5 V vs Li/Li+).Unfortunately, huge volume expansion (310% at full lithiation of Si) due to the lithium ion diffusion during the lithiation/delithiation process causes drastic capacity fade because of the high internal stresses, loss of electrical contact and the formation of non-electronic and ionic conductive passivation film between the anode surface and electrolyte. Low electrical conductivity of silicon is also another problem that remarkably hinders the rate performance. In the present work, above mentioned shortcomings are overwhelmed by incorporating tri(ethylene glycol) (TEG) groups over phenylene base units as side chains on the framework of the PFP based conductive polymer. Polyvinylpyrrolidone (PVP) was also used as adhesive to enhance the property of binding, thus decreasing stress-induced cracks. The synthesis was achieved through Suzuki polycondensation reaction in the presence of Pd(PPh3)4 catalyst by using independently prepared TEG functionalized dibromo benzene in conjunction with dioctylfluorene-diboronic acid bis(1,3-propanediol) ester. The obtained conductive and flexible polymer was used as a binder for Si-anode with high performance. It was demonstrated that the designed and fabricated binder polymer with multi-functionality displays a high electronic conductivity, mechanical strength, high polarity, adhesion, and more importantly, the electrolyte uptake arising from its excellent ductility. Figure 1

Lithium-ion batteries (LIP) are becoming more common in portable electronic devices due to their high energy density, lack of memory effect, and high charge and discharge rate capabilities. Li-ion batteries are a relatively new technology, first marketed in the early 1990s, and research and development work is ongoing to improve safety and increase capacity, charge/discharge rate, and lifetime. In this work, the development of a synthetic process for the next generation of coronene-based polymeric binders with high conjugation and very ductile backbone structures along the chains was showed. The reaction proceeds through the free-radical polymerization of the acrylate backbone. The polymerization process does not require the transition metal catalyst and has relaxed requirements to the experimental condition. In summary, a new type of side-chain electron-conducting polymer binder was developed and it showed the stable and high capacities at a C/3 cycle rate. Figure 1

Control over porous electrode microstructure is critical for the continued improvement of lithium ion batteries. This paper describes a convenient and economical method for controlling electrode porosity, thereby enhancing material loading and stabilizing the cycling performance of lithium ion electrodes. We demonstrates an areal capacity of ~4 mAh/cm2 at a C/10 rate (0.51 mA/cm2) and an areal capacity of 3 mAh/cm2 at a C/3 rate (1.7 mA/cm2), one of the highest material loadings reported for a Si-based anode at such a high cycling rate. X-ray microtomography confirmed the improved porous architecture of the Si-based electrode. The method developed here is expected to be compatible with the state-of-the-art lithium ion battery industrial fabrication processes, and therefore holds great promise as a practical technique for boosting the electrochemical performance of lithium ion batteries without changing material systems.

Carbon nanotubes (CNTs) possess unique structural, mechanical, thermal and electronic properties, and have been proposed to be used for applications in many fields. However, to reach the full potential of the CNTs, many problems still need to be solved, including the development of an easy and effective purification procedure, since synthesized CNTs contain impurities, such as amorphous carbon, carbon nanoparticles and metal particles. Different purification methods yield different CNT characteristics and may be suitable for the production of different types of CNTs. In this study, the effect of different purification chemicals on carbon nanotube quality was investigated. CNTs were firstly synthesized by chemical vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide (MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O) solution. The synthesis parameters were selected as: the synthesis temperature of 800°C, the iron content in the precursor of 5% and the synthesis time of 30 min. The liquid phase oxidation method was applied for the purification of the synthesized CNT materials. Three different acid chemicals (HNO3, H2SO4, and HCl) were used in the removal of the metal catalysts from the synthesized CNT material to investigate the possible effects of each acid solution to the purification step. Purification experiments were carried out at two different temperatures (75 and 120 °C), two different acid concentrations (3 and 6 M) and for three different time intervals (6, 8 and 15 h). A 30% H2O2 : 3M HCl (1:1 v%) solution was also used in the purification step to remove both the metal catalysts and the amorphous carbon. The purifications using this solution were performed at the temperature of 75°C for 8 hours. Purification efficiencies at different conditions were evaluated by thermogravimetric analysis. Thermal and electrical properties of CNTs were also determined. It was found that the obtained electrical conductivity values for the carbon nanotubes were typical for organic semiconductor materials and thermal stabilities were changed depending on the purification chemicals., {"references":["P.X. Hou, C. Liu, H.M. Cheng, \"Purification of Carbon Nanotubes\",\nCarbon, 46 (2008) 2003.","Z. Li, W. Lin, K. Moon, S. J. Wilkins, Y. Yao, K. Watkins, L.\nMorato, C. Wong, \"Metal catalyst residues in carbon nanotubes\ndecrease the thermal stability of carbon nanotube/silicone\ncomposites\", Carbon, S0008-6223(11)00405-2 (Accepted\nManuscript)","G. Sun, G. Chen, Z. Liu, M. Chen, \"Preparation, crystallization,\nelectrical conductivity and thermal stability of syndiotactic\npolystyrene/carbon nanotube composites\", Carbon 48 (2010) 1434-\n1440","B. Scheibe, E. Borowiak-Palen, R.J. Kalenczuk, \"Enhancement of\nthermal stability of multiwalled carbon nanotubes via different\nsilanization routes\", Journal of Alloys and Compounds 500 (2010)\n117-124.","Y. Yu, C. Ouyang, Y. Gao, Z. S─▒, W. Chen, Z. Wang, G. Xue,\n\"Synthesis and Characterization of Carbon Nanotube/Polypyrrole\nCore-Shell Nanocomposites via In Situ Inverse Microemulsion\",\nJournal of Polymer Science Part A: Polymer Chemistry 43(2005) 23","Q. Zhang, S.Rastogi, D. Chen, D. Lippits, P. J. Lemstra, \"Low\npercolation threshold in single-walled carbon nanotube/high density\npolyethylene composites prepared by melt processing technique\",\nCarbon 44 (2006) 778-785","S. Curran, D.L. Carroll, P.M. Ajayan, P. Redlich, S. Roth, M. R├╝hle,\nW. Blau, \"Picking needles from the nanotube-haystack\", Advanced\nMaterials 1998;10(14):1091-3.","H. Athalin, S. Lefrant, \"A correlated method for quantifying mixed\nand dispersed carbon nanotubes: analysis of the Raman band\nintensities and evidence of wavenumber shift\". J. Raman Spectrosc.\n2005;36: 400-8","W.E. Alvarez, B. Kitiyana, , A. Borgn, , D.E. Resasc, \"Synergism of\nCo and Mo in the catalytic production of single-wall carbon\nnanotubes by decomposition of CO\", Carbon 2001;39: 547-58.\n[10] E. Dujardin, T. Ebbesen, A. Krishnan, M. Treacy , \"Purification of\nsingle shell nanotubes\". Adv Mater 1998;10:611-3."]}

The aim of this study was to synthesize the single walled carbon nanotubes (SWCNTs) and determine their hydrogen storage capacities. SWCNTs were firstly synthesized by chemical vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide (MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O) solution. The synthesis parameters were selected as: the synthesis temperature of 800°C, the iron content in the precursor of 5% and the synthesis time of 30 min. Purification process of SWCNTs was fulfilled by microwave digestion at three different temperatures (120, 150 and 200 °C), three different acid concentrations (0.5, 1 and 1.5 M) and for three different time intervals (15, 30 and 60 min). Nitric acid (HNO3) was used in the removal of the metal catalysts. The hydrogen storage capacities of the purified materials were measured using volumetric method at the liquid nitrogen temperature and gas pressure up to 100 bar. The effects of the purification conditions such as temperature, time and acid concentration on hydrogen adsorption were investigated., {"references":["M.S. Dresselhaus, G. Dresselhaus, P.C. Eklund, D.E.H. Jones, \"Science\nof Fullerenes and Carbon Nanotubes\", Academic Press, San Diego,\n1996, pp. 1-985.","M. Chen, H.W. Yu, J.H. Chen, H.S. Koo, \"Effect of purification\ntreatment on adsorption characteristics of carbon nanotubes\", Diam\nRelat Mater 2007;16:1110-5.","P. Ciambelli, D. Sannino, M. Sarno, C. Leone B. Smith, \"Wide\ncharacterisation to compare conventional and highly effective\nmicrowave purification and functionalization of multi-wall carbon\nnanotubes\", Thin Solid Films 519 (2011) 2121-2131.","Y.J. Chen, M.L.H. Green, J.L. Griffin, J. Hammer, R.M. Lago, S.C.\nTsang. \"Purification and opening of carbon nanotubes via bromination\",\nAdv Mater 1996, 8(12):1012-5.","A.G. Rinzler, J. Liu, H. Dai, P. Nikolaev, C.B. Huffman, F. Rodr─▒guez-\nMac─▒as, \"Large-scale purification of single-wall carbon nanotubes:\nprocess, product, and characterization\", Appl Phys A1998;67(1):29-37.","Y.H. Wang, H.W. Shan, R.H. Hauge, M. Pasquali, R.E. Smalley, \"A\nhighly selective, one-pot purification method for singlewalled carbon\nnanotubes\", J Phys Chem B 2007;111(6):1249-52.","X.R. Ye, L.H. Chen, C. Wang, J.F. Aubuchon, I.C. Chen, A.I. Gapin,\n\"Electrochemical modification of vertically aligned carbon nanotube\narrays\", J Phys Chem B 2006;110(26):12938-42.","Y. Wang, L. Gao, J. Sun, Y.Q. Liu, S. Zheng, H. Kajiura, \"An integrated\nroute for purification, cutting and dispersion of single-walled carbon\nnanotubes\", Chem Phys Lett 2006,;432(1-3):205-8.","H.Z. Geng, T.H. Kim, S.C. Lim, H.K. Jeong, M.H. Jin, Y.W. Jo, Y.H.\nLee, \"Hydrogen storage in microwave-treated multi-walled carbon\nnanotubes\", International Journal of Hydrogen Energy 35, 2010:2073-\n2082\n[10] S. Curran, D.L. Carroll, P.M. Ajayan, P. Redlich, S. Roth, M. R├╝hle, W.\nBlau, \"Picking needles from the nanotube-haystack\", Advanced\nMaterials 1998;10(14):1091-3.\n[11] H. Athalin, S. Lefrant, \"A correlated method for quantifying mixed and\ndispersed carbon nanotubes: analysis of the Raman band intensities and\nevidence of wavenumber shift\". J. Raman Spectrosc. 2005;36: 400-8\n[12] W.E. Alvarez, B. Kitiyana, , A. Borgn, , D.E. Resasc, \"Synergism of Co\nand Mo in the catalytic production of single-wall carbon nanotubes by\ndecomposition of CO\", Carbon 2001;39: 547-58.\n[13] H.M. Kingston, S.J. Haswell, \"Microwave-Enhanced Chemistry\n(Fundamentals, Sample Preparation, and Applications)\", American\nChemical Society,Washington,DC, 1997."]}

High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated to the reduction of thickness and porosity, as well as the increase of density. SiO particle size remains unchanged after calendaring. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and over-calendered electrode. The calendered electrode has a highdensity of ~1.2 g/cm3. A high loading electrode with an areal capacity of ~3.5 mAh/cm2 at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendaring method. Figure 1