Lithium Sulphur Batteries

S+C cathode material was prepared by simple solid-state reaction in ball mill. Content of sulphur was approximately 80 wt. % in final sample. Cyclic voltammetry and galvanostatic charge/discharge techniques were used for characterization of the samples. Initial discharge capacity observed for S+C sample was 600 mAh/gsulfur. Capacity loss for S+C sample after 30th cycles was 66 %. Cycling loss is due to insoluble polysulfide formation. In this paper I present fundamental characteristics of Li-S batteries. This paper presents a principle of Li-S batteries, fundamental measurement and their evaluation. I present the techniques of measurement and preparation of cathode materials

Advanced Materials for Rechargeable Lithium-Sulfur Batteries

Rechargeable batteries are essential power supplies for our daily life, and they are widely used in portable electronics, hybrid electric vehicles, and grid energy storage. Lithium-ion (Li-ion) batteries, which have the highest energy density among rechargeable batteries, have reached the capacity limits of current electrode materials, such as transition metal oxides (e.g., LiCoO2, LiMn2O4, and LiFePO4). To meet the increasing demand of high energy density batteries, rechargeable lithium-sulfur (Li-S) batteries are considered as one of the most promising systems with significant potential for many practical applications. Sulfur has a theoretical capacity of 1,672 mAh/g by taking two electrons per atom, which is an order of magnitude higher than those of transition metal oxides. However, several challenges impede practical application of Li-S batteries, such as high resistivity of sulfur, dissolution of intermediate polysulfides, and shuttle of these polysulfides from cathode to anode in Li-S batteries. Significant improvements have been achieved over the past years, but further improvements and better understanding of Li-S batteries are still needed. This poster will present several strategies that have been developed including sulfur-conductive polymer nanocomposites, lithium/dissolved polysulfide cells, sandwiched Li2S electrodes, and in situ formed Li2S cathodes. A nanolayer of conductive polypyrrole was fabricated on sulfur particles, which can enhance electrical conductivity and reduce dissolution of polysulfides. Binder-free carbon nanotube current collector was used in lithium/dissolved polysulfide cells, which exhibit unprecedented capaciteis of 1,600 mAh/g in the first cycle and over 1,400 mAh/g after 50 cycles. Lithium metal anode is used in current Li-S batteries since the sulfur cathodes do not have any lithium in the initial stage, which is a safety hazard. Lithium-rich sulfur cathode materials such as Li2S can allow a variety of non-lithium metal anodes to be used, which can advance the Li-S battery technology to an unprecedented level. However, the high reactivity of Li2S results in limited approaches that have been explored. A sandwiched Li2S electrode consisting of two layers of carbon nanotube paper has been developed which shows high capacities and high rate capabilities. In addition, a novel in situ formed Li2S cathode is developed, which utilizes lithiated graphite as a lithium donor to convert lithium polysulfide Li2S6 to the end discharge product Li2S. These materials and strategies are promising for practical applications

Comparison of the state of lithium-sulphur and lithium-ion batteries applied to electromobility

The market share in electric vehicles (EV) is increasing. This trend is likely to continue due to the increased interest in reducing CO2 emissions. The electric vehicle market evolution depends principally on the evolution of batteries capacity. As a consequence, automobile manufacturers focus their efforts on launching in the market EVs capable to compete with internal combustion engine vehicles (ICEV) in both performance and economic aspects. Although EVs are suitable for the day-to-day needs of the typical urban driver, their range is still lower than ICEV, because batteries are not able to store and supply enough energy to the vehicle and provide the same autonomy as ICEV. EV use mostly Lithium-ion (Li-ion) batteries but this technology is reaching its theoretical limit (200–250¿Wh/kg). Although the research to improve Li-ion batteries is very active, other researches began to investigate alternative electrochemical energy storage systems with higher energy density. At present, the most promising technology is the Lithium-Sulphur (Li-S) battery. This paper presents a review of the state of art of Li-Sulphur battery on EVs compared to Li-ion ones, considering technical, modelling, environmental and economic aspects with the aim of depicting the challenges this technology has to overcome to substitute Li-ion in the near future. This study shows how the main drawbacks for Li-S concern are durability, self-discharge and battery modelling. However, from an environmental and economic point of view, Li-S technology presents many advantages over Li-ion.Peer ReviewedPreprin

The technologies for processing of waste Li batteries

Tato bakalářská práce je zaměřena na možnosti využití Li-ion baterií a jejich recyklaci. V posledních letech dochází k nárůstu poptávky po Li-Ion bateriích, a to v několika průmyslových odvětvích. S tím je očekáván velký nárůst odpadních baterií. V práci jsou ojasněny současné technologické postupy a procesy při recyklaci. V závislosti na zvyšujícím se množství odpadních Li-Ion baterií bylo v praktické části analyzováno materiálové složení vybraných typů baterií. Podíl jednotlivých složek byl stanoven pomocí hmotnostní bilance u Li-Ion baterií používaných v mobilních telefonech. Dále byly zhodnoceny možnosti jejich využití včetně recyklace.My Bachelor study is focused on mapping opportunities in using Li-ion batteries and their way of recycling. Several last years we can see the progress in demand for using Li-Ion batteries in industry. In that case we could expect increased amount of waste batteries. In these study I introduce actual technology processes including processes of their recycling. According to increased amount waste batteries Li-Ion batteries I have analysed in my study the material composition of several type of waste batteriesbatteries. The amount of individual and specific components of Li-Ions batteries used in mobil phones was set up by using mass balance methodology. I have evaluated their possibiities for their other using and recycling as well.636 - Katedra materiálového inženýrstvívýborn

Enhancing electrochemical intermediate solvation through electrolyte anion selection to increase nonaqueous Li-O2_2 battery capacity

Among the 'beyond Li-ion' battery chemistries, nonaqueous Li-O$_2$ batteries have the highest theoretical specific energy and as a result have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O$_2$ batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that further decrease the overall electrochemical stability of the system, thereby deleteriously affecting battery rechargeability. In this study, we report that a significant enhancement (greater than four-fold) in Li-O$_2$ cell capacity is possible by appropriately selecting the salt anion in the electrolyte solution. Using $^7$Li nuclear magnetic resonance and modeling, we confirm that this improvement is a result of enhanced Li$^+$ stability in solution, which in turn induces solubility of the intermediate to Li$_2$O$_2$ formation. Using this strategy, the challenging task of identifying an electrolyte solvent that possesses the anti-correlated properties of high intermediate solubility and solvent stability is alleviated, potentially providing a pathway to develop an electrolyte that affords both high capacity and rechargeability. We believe the model and strategy presented here will be generally useful to enhance Coulombic efficiency in many electrochemical systems (e.g. Li-S batteries) where improving intermediate stability in solution could induce desired mechanisms of product formation.Comment: 22 pages, 5 figures and Supporting Informatio

Development of sulfur based polymers for rechargeable lithium batteries

Lithium-ion (Li-ion) batteries are in the front edge of recent achievements concerning energy storage. However, Li-ion devices are reaching their maximum regarding energy density storage which restricts their appiicatíon in systems with large power needs, such as electric vehicles. Driven by this shortcoming, in the last few years, Lithium-Sulfur (Li-S) batteries are being considered as an alternative for the exploitatíon of energy storage and conversion systems with improved performance. Indeed, to the S cathodes is associated a theoretical specifíc capacity of 1672 mA h g-1 and a specifíc energy of 2600 W h kg-\ which are several times higher than the correspondent to other possible systems. The relative low atomic weight of S in comparison with other elements (e.g. cobalt) and the multí-electron transfer reactíons in the pair Li/S are at the source ofthis superior theoretícal performance of Li-S batteries.Este trabalho foi financiado por: projeto POCI-01-0145-FEDER-006984 - Laboratório Associado LSRE-LCM - financiado pelo Fundo Europeu de Desenvolvimento Regional (FEDER), através do COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI)info:eu-repo/semantics/publishedVersio

Trace doping of multiple elements enables stable battery cycling of LiCoO2 at 4.6 V

LiCoO2 is a dominant cathode material for lithium-ion (Li-ion) batteries due to its high volumetric energy density, which could potentially be further improved by charging to high voltages. However, practical adoption of high-voltage charging is hindered by LiCoO2’s structural instability at the deeply delithiated state and the associated safety concerns. Here, we achieve stable cycling of LiCoO2 at 4.6 V (versus Li/Li+) through trace Ti–Mg–Al co-doping. Using state-of-the-art synchrotron X-ray imaging and spectroscopic techniques, we report the incorporation of Mg and Al into the LiCoO2 lattice, which inhibits the undesired phase transition at voltages above 4.5 V. We also show that, even in trace amounts, Ti segregates significantly at grain boundaries and on the surface, modifying the microstructure of the particles while stabilizing the surface oxygen at high voltages. These dopants contribute through different mechanisms and synergistically promote the cycle stability of LiCoO2 at 4.6 V