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Sodium ion batteries (SIBs) are promising technique for energy storage applications. Cathode materials are keys to improve the energy density of SIBs. P2-type layered cathodes with low Na ion diffusion barrier attract great attention. However, it suffers structural instability at a high working voltage. Though many attempts were made, the cycle stability of P2-type layered cathodes with a high working voltage is still not satisfactory. In this work, zinc was used as a doping element for modification. When the doping amount is x = 0.1 (Na0.7Ni0.25Mn0.65Zn0.1O2), it presents enhanced cycle stability in the voltage range of 2.5–4.2 V. The impacts of calcination temperature and cooling methods were investigated. It was found that the material shows excellent stability when the material was calcined at 950 °C followed by natural cooling, the discharge capacity is 64.9 mAh g−1 over 1000 cycles with a capacity retention of 84.0% after 1000 cycles at 170 mA g−1, superior to those reported in literature. In situ XRD reveals a reversible phase transition from P2 to OP4 at the high voltage contributes to the excellent cycle stability. [ABSTRACT FROM AUTHOR]

The room temperature overcharge behavior of high-power type lithium-ion batteries (maximum discharge rate 50 C) with Li(Ni1/3Mn1/3Co1/3)O2 as the cathode is carefully explored in this work at varied current rates. There are five stages in the overcharge procedure. Under conditions where battery rupture is a warning sign and charging is quickly stopped, overcharge at the current rates not exceeding 3 C does not lead to uncontrollable combustion and explosion. There are differences in the overcharge voltage characteristics of the battery at different charging rates. As the charge current rates increase, the amount of power that the lithium-ion battery can receive before the battery outsourcing ruptures decreases, while the peak voltage increases. The internal resistance at 0.5 C overcharge is measured by the hybrid pulse power characterization method, and the reason for the rapid rise of voltage in the stage 3 is the rapid increase of the polarized internal resistance. Then, the accumulated heat analysis knows that the internal heat production is mainly contributed by the side reactions. In addition, a large amount of H2, CO, CH4, C2H4 and CO2 are collected at the moment of battery outsourcing ruptures. These findings are useful for the battery management system's safety monitoring function, which is important for the safe use of high-power type lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In this work the nanocomposite of vanadium oxide with conducting polymer poly(3,4-ethylenedioxythiophene) (VO@PEDOT) was obtained by microwave-assisted hydrothermal synthesis. The detailed study of its structural and electrochemical properties as cathode of aqueous zinc-ion battery was performed by scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The initial VO@PEDOT composite has layered nanosheets structure with thickness of about 30–80 nm, which are assembled into wavy agglomerated thicker layers of up to 0.3–0.6 μm. The phase composition of the samples was determined by XRD analysis which confirmed lamellar structure of vanadium oxide V10O24∙12H2O with interlayer distance of about 13.6 Å. The VO@PEDOT composite demonstrates excellent electrochemical performance, reaching specific capacities of up to 390 mA∙h∙g−1 at 0.3 A∙g−1. Moreover, the electrodes retain specific capacity of 100 mA∙h∙g−1 at a high current density of 20 A∙g−1. The phase transformations of VO@PEDOT electrodes during the cycling were studied at different degrees of charge/discharge by using ex situ XRD measurements. The results of ex situ XRD allow us to conclude that the reversible zinc ion intercalation occurs in stable zinc pyrovanadate structures formed during discharge. [ABSTRACT FROM AUTHOR]

The extensive application in recent years of lithium-ion batteries (LIBs) based on an LiFePO4 (LFP) cathode in electric vehicles will lead to a large amount of scrapped LFP in the foreseeable future. Therefore, recycling these scrapped cathode materials appropriately will become an extremely important issue. Here, a facile and green method is developed to directly regenerate scrapped LFP into a fresh cathode. We propose a re-lithiation approach that intercalates lithium ions into scrapped LFP in an aqueous solution system. Specifically, the configuration of the recycling device is a H-type electrolytic bath, in which the cathode and anode electrolytes are separated by an anion-exchange membrane, a zinc plate is used as the anode, the scrapped LFP suspension is regarded as the cathode, and the electrolyte is lithium salt aqueous solution. The regenerated LFP is obtained via a discharging process. It is found that the effectiveness of the recycling process is directly related to the parameters of the discharge current (mA) and theoretical intercalation amount of lithium (TIA). The results show that the performance of LFP recycled at a current of 5 mA and 150%-TIA is the best; it has high lithium content and better crystallinity, and it also exhibits excellent electrochemical performance with a high discharge capacity of 134.0 mA h g−1 at 1C and a capacity retention rate of 85.5% after 300 cycles. Furthermore, we adopt FTIR spectroscopy to assess the quality of the regenerated LFP intuitively and simply, thus providing a feasible monitoring standard for industrial production. [ABSTRACT FROM AUTHOR]

[Display omitted] Organic electrode materials are considered as ideal candidates for the next generation of rechargeable batteries owing to their safety, environmental friendliness, sustainability, structure designability, and low price. Among them, organosulfur compounds are promising cathodes for advanced lithium batteries due to their high theoretical capacity and working potential, and have attracted much attention. However, some intrinsic problems such as low conductivity, high solubility in electrolytes, and poor stability have seriously affected the promising perspective of organosulfur cathode materials. This review introduces the latest researches on the basic properties and reaction mechanisms of organosulfur compounds (thioether, organodisulfide, organopolysulfide, and sulfurized polyacrylonitrile) and summarizes the design strategies to improve their capacity, voltage plateau, cycling stability, and rate performance caused by intrinsic problems. In this review, significant challenges and prospects of organosulfur compounds as cathode materials of lithium batteries are investigated. The purpose of this review is to provide meaningful guidance for researchers to promote the development of organosulfur cathode materials. [ABSTRACT FROM AUTHOR]

Abstract Li-rich layered Li 2 MnO 3 is of great attraction for high energy lithium ion batteries. However, its cycling is still needed for improvements. Here we report a hollow microsphere-structured xLi 2 MnO 3 ·(1-x)LiNiO 2 (x = 0.3–0.7) that is synthesized by using in-situ template-sacrificial strategy. Powder X-ray diffraction (XRD) and scanning electron microscope (SEM) characterizations prove that the xLi 2 MnO 3 ·(1-x)LiNiO 2 (x = 0.3–0.7) are based on monoclinic Li 2 MnO 3 with α-NaFeO 2 layered structure in which Li+ ions are orderly arranged in the transition metal layers, and the hollow-microspheres have diameters of ∼3 μm. Electrochemical results show that the optimal ratio of Li 2 MnO 3 /LiNiO 2 is 0.6/0.4. As a consequence, the stabilized discharge capacity of 0.6Li 2 MnO 3 ·0.4LiNiO 2 (0.6LLMNO) is ∼210 mAh g−1 after the first few cycles. This shows that appropriate amount Ni substitution for Mn in Li 2 MnO 3 helps to improve the specific capacity and cycling stability. Graphical abstract Adopt a facile in-situ template-sacrificial strategy to synthesize hollow-spherical xLi 2 MnO 3 •(1-x)LiNiO 2 (x = 0.3–0.7), which are based on monoclinic Li 2 MnO 3 with α-NaFeO 2 layered structure. The 0.6Li 2 MnO 3 ·0.4LiNiO 2 exhibits the best cycling stability and specific capacity. Therefore, a moderate Ni content can not only stabilize the ordered layered structure but also improve electrochemical performance. Image 1 Highlights • Li-rich layered materials were synthesized through template-sacrificial strategy. • Li+ in inner of hollow microspherical was activated after the first few cycles. • 0.6Li 2 MnO 3 ·0.4LiNiO 2 has a large specific surface area and excellent conductivity. • 0.6Li 2 MnO 3 ·0.4LiNiO 2 has no apparent capacity fading in 110 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen vacancies and Ti3+ were both introduced into a tubular brush-like cathode structure, in which nano-needled TiO 2 grew in situ on carbon textile. • The tubular brush like structured free-standing cathode showed facilitated ORR and OER kinetics. • TiO 2 evenly growing on carbon cloth effectively avoided the side reaction from carbon corrosion, which extended the lifespan of lithium-oxygen battery. • The synergistic effect between oxygen defected-TiO 2 and RuO 2 accelerated charge transfer, and adjusted the electronic structure to achieve the surface-mediated formation mechanism of thin film lithium peroxide. • An ultra-long life of more than 300 cycles was achieved in the battery with the CT@TiO 2 -RuO 2 cathode at a high current density of 0.3 mA cm−2. Rational designed cathode including the surface engineering of catalyst e.g. defect creation and the precise selection of catalyst that could avoid the side reaction of carbon have been verified of great concern in achieving long-life lithium-oxygen batteries. Herein, oxygen vacancies and Ti3+ were both introduced into a tubular brush-like cathode structure, in which nano-needled TiO 2 grew in situ on carbon textile (CT), and further enhancement of the catalytic performance was achieved by loading RuO 2. The introduction of oxygen vacancies and Ti3+ in TiO 2 could regulate the charge overpotential, and the synergistic effect between ruthenium dioxide and titanium dioxide accelerated charge transfer, and adjusted the electronic structure to achieve the surface-mediated formation mechanism of thin film lithium peroxide. Besides, TiO 2 grew evenly on the surface of carbon matrix, thus restraining the carbon corrosion. Thus, CT@TiO 2 and CT@TiO 2 -RuO 2 provided low overpotentials of 0.94 V and 0.69 V and superior cycle life. Meanwhile, an ultra-long life of 317 cycles was achieved in the battery with the CT@TiO 2 -RuO 2 cathode at a high current density of 0.3 mA cm−2. [ABSTRACT FROM AUTHOR]