Optimizing anion storage performances of graphite/ non-graphitic carbon composites as cathodes for dual-ion batteries

Anion intercalation capacity of graphite cathode is a limiting factor towards the development of dual-ion energy storage devices. A large portion of electrochemically active sites in graphite lattice remains inaccessible to anions due to the instability of electrolytes beyond 5 V. Strategy to composite graphitic intercalation along with surface storage from non-graphitic carbons to enhance capacity is explored in this work. Optimizations are performed to determine the best ratio of graphitic and non-graphitic carbons, and to find out the blend of physical properties of non-graphitic carbons that aid the surface contribution to the greatest extent. Besides, it is also optimized to obtain the maximum achievable lifetime and efficiency, suitable active material loading for balancing energy-power output, and the safest upper cut-off voltage for trading off capacity against cycle life. Surface area, pore size, functional groups, and doped elements govern the electrochemical properties of non-graphitic carbons. A composite of graphite with high surface area carbon (2477 m2 g − 1) in a 75:25 ratio doubles the capacity, whereas the composite of graphite and reduced graphene oxide at the same ratio yields prolonged cycle life at 100 mA g − 1 within 2.0–5.0 V. The capacity improvement is invariably reproducible in dual carbon cell using composite materials as both electrodes

IIT Hyderabad to collaborate on development of lithium-ion batteries for electric vehicles

The Indian Institute of Technology, in collaboration with ItsEV Inc, plans to develop lithium-ion batteries for various applications, including electric vehicles

High-capacity electrode materials for electrochemical energy storage: Role of nanoscale effects

This review summarizes the current state-of-the art electrode materials used for high-capacity lithium-ion-based batteries and their significant role towards revolutionizing the elec- trochemical energy storage landscape in the area of consumer electronics, transportation and grid storage application. We discuss the role of nanoscale effects on the electrochemical performance of high-capacity battery electrode materials. Decrease in the particle size of the primary electrode materials from micron to nanometre size improves the ionic and electronic diffusion rates signifi- cantly. Nanometre-thick solid electrolyte (such as lithium phosphorous oxynitride) and oxides (such as Al 2 O 3 ,ZnO,TiO 2 etc.) material coatings also improve the interfacial stability and rate capability of a number of battery chemistries. We elucidate these effects in terms of different high-capacity battery chemistries based on intercalation and conversion mechanism

Development of LMR-NMC Based Cathodes and Si-Based Anodes for High Energy Density Lithium-Ion Batteries

Li-ion Batteries (LIBs) have attracted much attention in recent times among all the rechargeable batteries available today due to highest energy density (150-200 Wh kg-1), cell voltage (3.7 V), good cycle life (1000-1500) and low self-discharge (2% per month). Lithium being the third lightest element, has high potential (-3.07 V vs. SHE), high capacity (3861 mAh g-1) is an excellent anode material for LIBs. However, pure Li is very reactive to moisture in air and also form dendrites in LIBs upon charging to high voltages. The Li dendrites can penetrate through the separator causing short circuit which leads to development of heat, fire or explosion. The origin of LIB lies in the discovery that Li+ ions can be reversibly intercalated within or de-intercalated from the van der Waals gap between graphene sheets of carbonaceous materials at a potential close to the Li/Li+. Thus, lithium metal is replaced by carbon based anode materials for LIBs and the problems associated with pure metallic lithium mitigated. LIBs were first introduced into market by Sony Corporation of Japan during 1991 by using LiCoO2 cathode and graphite anode in standard electrolyte solution containing LiPF6 salt in alkyl carbonates. Since then, the LIB market has grown from an R&D interest and the current market value close to US$40 billion. The world demand for primary and secondary batteries is forecasted to be US$120 billion in 2019 in which rechargeable LIBs has market share about 37%

Nano Structured Reduced Graphene Oxide (RGO) Coated TiO2 as Negative Electrode Additive for Advanced Lead acid Batteries

Lead-acid batteries(LABs)remains to be the most successful energy storage systems ever developed. Although lead-acid battery designs have been optimized in the past in several different ways, there are still certain challenges facing lead-acid battery designers, such as grid corrosion at the positive electrode, sulfation at both the electrodes, and poor charge acceptance of positive electrode, larger curing and formation time and more significantly low energy density because of high atomic weight of lead. So the current research efforts in electrochemical energy storage are directed towards achieving high energy density with reduced cost and less weight and reduce sulation. To overcome the issues of sulfation and formation efficiency of the electrodes we propose here reduced graphene oxide (RGO)coated TiO2 as a negative electrode additive for advanced Lead Acid Batteries(LAB). Addition of 0.5 wt. % of RGO coated TiO2 in to the negative active mass reduces sulfation, consequently increase battery formation efficiency from 3 cycle to 1 cycle, 10-20% increase in discharge capacity (C-rate performances). The additive also increases the battery life under high rate discharge conditions

Synthesis and Characterization of Nano - Structured Lead and Lead Dioxide Electrodes for Advanced Lead - Acid Batteries - A Literature Survey

Nowadays batteries are used in almost all areas of living and hence they are becoming increasingly important to our life. Thus the critical issue to address is the reliability of the battery in these battery applications. It is essential due to its standby application and also stabilizes the electrical network in the automobiles which supplies energy even in the stationary position. They many design, many sizes and broad voltages. They have good It is known that the total capacity of a battery drops when it is charged and discharged multiple times i.e. they have limited cycle durability. And if it is found that a battery is too weak to offer sufficient energy then it should be replaced at the right time. But the current problem is that there is no reliable method available to estimate the remaining capacity of battery and to quantify the capacity loss. The only way of capacity estimation is complete discharge but it has a negative effect on the battery plates therefore it should not be used too frequently. Also it stabilizes electrical network of automobiles through voltage by virtue of which also provides continuously supply energy even in stationary mode. Valve regulated acid battery overcome these problems acid stratification, hydrogen evolution at negative, electrode grid corrosion as they happens in vented batteries.This thesis summarizes the research work in the development of a new synthesis of approach of Synthesis and Characterization of Nano-Structured Lead Dioxide Electrodes for Advanced Lead-Acid Batteries which is used as cathode and Make a battery using commercial material and take a charge/discharge at different rates and impedance. The main reason of goal why contemplating nanostructured over micro structured material because Prominent electronic and chemical properties, short diffusion paths for ion transport and electronic conduction. The nanomaterial particle size together with the highly porous microstructure and the large surface area lead to enhanced electrochemical activity of the nanostructured PbO2 electrode i.e. Ease of curing and electrochemical formation processes, good amount of active material utilization, hence good capacity (less sulfation) and cycle life. High surface area allow to fabricate batteries with small size and light weight provides High Energy Density

Boron Doped Graphene as a Negative Electrode Additive for High Performance Lead-Acid Batteries

Lead-acid battery remains the most successful battery system ever developed. Although lead-acid battery designs have been optimized in the past in several different ways, there are still certain new challenges faced by lead-acid battery designers, as additional failure modes become evident in various end-uses. In this work we have studied the effect of Boron doped graphene as an additive for the negative electrode in lead acid battery. B-doped graphene synthesized from the solvothermal method. Boron doping confirmed by the different characterization methods. X-ray photoelectron spectroscopy (XPS) measurement confirms the atomic level of boron (3.11 %) is doped into the boron doped graphene. Here we have systematically investigated the various percentages of the Boron doped graphene (0, 0.25, 0.5 and 1wt. %) additive added to the negative active material (NAM). Besides this study involves optimized the additive w.r.t negative active material and percentage of boron in boron doped graphene, it is found that 0.25 wt.% B-doped graphene additive in negative electrode which contains around 3% of Boron doping in the graphene shows optimum results. Boron doped graphene additive shows the impressive electrochemical performance in first discharge capacity, ~80% increases the capacity compared to the without born doped additive. An increase in capacity by 15-20% at lower C rates and the increase in capacity is almost double at higher C rates which indicates that this modified additive can be used for potential application in lead acid battery. Charge transfer dependent on the holes present the boron doped graphene and significant changes in the electronic structure of the graphene. Our results confirm the boron doping onto the graphene lattice it gives superior electrochemical performances and high rate partial charge cycling in lead acid batteries negative electrode additive

Binder free Silicon Anodes for Advanced Lithium Ion Batteries

Silicon has emerged as an attractive anode material for Lithium Ion Batteries since it has a high theoretical capacity of 4200 mAh/g, corresponding to the formation of Li22Si5 alloy. Unlike graphite anodes which rely on intercalation and deintercalation of Li+, silicon anodes depend on an alloying-dealloying process. However, the formation of Li-Si binary alloys involves volume modification of ~400%, and the repeated expansion and contraction during lithiation- delithiation leads to pulverization and consequent failure of the cell. To meet this challenge, we have designed binder-free silicon anodes that can circumvent the problem of pulverization. This work describes the synthesis of Si nanoparticles (NPs) by reverse micelle approach, followed by structural characterization of the material by X -Ray diffraction, Scanning Electron Microscopy and Raman Spectroscopy. The electrochemical performance of the Si active material as anode material for Lithium Ion Batteries was tested in two-electrode Swagelok type cells using galvanostatic charge-discharge cycling at different levels of depth-of-discharge, and also by impedance spectroscopy. Two approaches have been employed in the designing of the electrodes: firstly, the Si NPs were manually embedded on Cu foil as current collector by the application of pressure, and secondly, chitosan, polypyrrole -hydrogel and P-Pitch were used as novel binders in developing 3D electrode architecture on carbon fibre

Magnesium & Fluorine Doped LMR-NMC Cathode Materials for High Energy Density Lithium-Ion Batteries

Lithium rich layered oxide (LMR-NMC) having composition Li1.2Mn0.55Ni0.15Co0.10O2 is considered as a potential candidate for cathode materials for high energy density lithium ion batteries for electric vehicles. The LMR NMC cathodes deliver capacity of > 250 mAh/g when they are operated between 2.5 V and 4.8V. However, LMR-NMC suffer from some drawbacks which limits its application in electric vehicles like poor conductivity, less interfacial stability, structural instability, which leads to poor cycle life. The major issue with LMR-NMC is the voltage decay. The reason for voltage fade is the structure transformation from layered to spinel structure which reduces the operating voltage from 4V to 3V consequently reducing the energy density from 1000 Wh/kg to 750 Wh/kg

Raman microscopy of lithium-manganese-rich transition metal oxide cathodes

Lithium-rich and manganese-rich (LMR) layered transition metal (TM) oxide composites with general formula xLi2MnO3 • (1- x)LiMO2 (M = Ni, Co, Mn) are promising cathode candidates for high energy density lithium ion batteries. Lithium-manganese-rich TM oxides crystallize as a nanocomposite layered phase whose structure further evolves with electrochemical cycling. Raman spectroscopy is a powerful tool to monitor the crystal chemistry and correlate phase changes with electrochemical behavior. While several groups have reported Raman spectra of lithium rich TM oxides, the data show considerable variability in terms of both the vibrational features observed and their interpretation. In this study, Raman microscopy is used to investigate lithium-rich and manganese-rich TM cathodes as a function of voltage and electrochemical cycling at various temperatures. No growth of a spinel phase is observed within the cycling conditions. However, analysis of the Raman spectra does indicate the structure of LMR-NMC deviates significantly from an ideal layered phase. The results also highlight the importance of using low laser power and large sample sizes to obtain consistent data sets