126 research outputs found

    Nanotechnology patenting in China and Germany:a comparison of patent landscapes by bibliographic analyses

    Full text link
    This article gives a general overview on the patent landscapes of China and Germany within the emerging field of nanotechnology. A keyword based search, using the search term “nano”, on SciFinder Scholar™ for the time period of 1985 to 2007 leads to 51,490 patent references overall and 12,979 Chinese and 2,901 German ones respectively. Bibliographic analyses focus on the historical trends in nanotechnology patenting as well as on major patent applicants, technological fields and international patenting strategies in China and Germany. They illustrate an above-average growth rate in nanotechnology patents for China, but a rather below-average one for Germany. Major differences in regard to the role of universities and research institutes in applied research and therefore as patent applicants are similarly emphasized as diverging international patenting strategies. Implications for future Chinese-German collaborations in applied nanotechnology research and potential improvements for future analyses are discussed.<br

    Transition Metal Oxide Anodes for Electrochemical Energy Storage in Lithium‐ and Sodium‐Ion Batteries

    Get PDF
    Lithium-ion batteries (LIBs) with outstanding energy and power density have been extensively investigated in recent years, rendering them the most suitable energy storage technology for application in emerging markets such as electric vehicles and stationary storage. More recently, sodium, one of the most abundant elements on earth, exhibiting similar physicochemical properties as lithium, has been gaining increasing attention for the development of sodium-ion batteries (SIBs) in order to address the concern about Li availability and cost—especially with regard to stationary applications for which size and volume of the battery are of less importance. Compared with traditional intercalation reactions, conversion reaction-based transition metal oxides (TMOs) are prospective anode materials for rechargeable batteries thanks to their low cost and high gravimetric specific capacities. In this review, the recent progress and remaining challenges of conversion reactions for LIBs and SIBs are discussed, covering an overview about the different synthesis methods, morphological characteristics, as well as their electrochemical performance. Potential future research directions and a perspective toward the practical application of TMOs for electrochemical energy storage are also provided

    ZnO-Based Conversion/Alloying Negative Electrodes for Lithium-Ion Batteries: Impact of Mixing Intimacy

    Get PDF
    Conversion/alloying materials, such as transition metal (TM)‐doped ZnO, are showing superior performance over pure ZnO due to the presence of the TM, enabling the reversible formation of Li2_{2}O due to the enhanced electronic conductivity within the single particle once being reduced to the metallic state upon lithiation. Herein, the impact of introducing Co as representative TM at the atomic level in ZnO compared with mixtures of nano‐ and microsized CoO and ZnO is investigated. While even rather simple mixtures provide higher capacities than pure ZnO, an intimate mixing of nanoparticulate CoO and ZnO leads to a further increase due to the more homogeneous dispersion of Co. Nonetheless, the “atomic mixing” via doping still provides the highest capacities—for both nano‐ and microparticles, thus highlighting the importance of the very fine distribution of Co (and generally the TM) for realizing effective electron conduction pathways to enable the reversible formation of Li2_{2}O

    Probing the 3‐step Lithium Storage Mechanism in CH3NH3PbBr3 Perovskite Electrode by Operando‐XRD Analysis

    Get PDF
    This is the pre-peer reviewed version of the following article: Probing the 3‐step Lithium Storage Mechanism in CH3NH3PbBr3 Perovskite Electrode by Operando‐XRD Analysis, which has been published in final form at: https://doi.org/10.1002/celc.201801291. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Organic‐inorganic hybrid materials have gradually become one of the most actively studied research fields due to their fascinating properties. The reaction between lithium and organic‐inorganic halide perovskite has just recently been proposed. However, the exact mechanisms taking place in this electrode material have not been fully elucidated, yet. To shed light on these processes an operando‐X‐ray diffraction study has been performed and is reported herein. According to our results the lithiation of CH3NH3PbBr3 entails three reaction steps, distinguishable during the initial galvanostatic lithiation for different Li‐ion molar content x: (1) the initial Li+ insertion into the perovskite phase in which pure perovskite and lithiated phases coexist (0 0.3, the formation of a Lix:CH3NH3PbBr3 phase with distinctive X‐ray diffraction peaks is clearly detected, which coexists with the pristine material, till abruptly both phases disappear at x∼1 and CH3NH3Br and Pb metal are formed. It is shown that this conversion reaction is an irreversible process. The proposed mechanism for lithium storage gives a complete perspective of the complex structural environment involving the use of perovskite materials as electrodes for Li‐ion batteries

    Novel sulfur-doped single-ion conducting multi-block copolymer electrolyte

    Get PDF
    Solid-state lithium batteries are considered one of the most promising candidates for future electrochemical energy storage. However, both inorganic solid electrolytes (such as oxide-based or sulfide-based materials) and polymer electrolytes still have to overcome several challenges to replace the currently used liquid organic electrolytes. An increasingly adopted approach to overcome these challenges relies on the combination of different electrolyte systems. Herein, we report the synthesis and characterization of a novel sulfur-doped single-ion conducting multi-block copolymer (SIC-BCE) system. This SIC-BCE may serve as interlayer between the electrodes and the sulfidic electrolyte such as Li6_{6}PS5_{5}Cl, thus benefitting of the high ionic conductivity of the latter and the favorable interfacial contact and electrochemical stability of the polymer. The polymer shows excellent ionic conductivity when swollen with ethylene carbonate and allows for stable stripping/plating of lithium, accompanied by a suitable electrochemical stability towards reduction and oxidation. First tests in symmetric Cu|SIC-BCE|Li6_{6}PS5_{5}Cl|SIC-BCE|Cu cells confirm the general suitability of the polymer to stabilize the electrode|electrolyte interface by preventing the direct contact of the sulfidic electrolyte with, e.g., metallic copper foils

    Decoupling segmental relaxation and ionic conductivity for lithium-ion polymer electrolytes

    Get PDF
    International audienceThe use of polymer electrolytes instead of liquid organic systems is considered key for enhancing the safety of lithium batteries and may, in addition, enable the transition to high-energy lithium metal anodes. An intrinsic limitation, however, is their rather low ionic conductivity at ambient temperature. Nonetheless, it has been suggested that this might be overcome by decoupling the ion transport and the segmental relaxation of the coordinating polymer. Here, we provide an overview of the different approaches to achieve such decoupling, including a brief recapitulation of the segmental-relaxation dependent ion conduction mechanism, exemplarily focusing on the archetype of polymer electrolytes – polyethylene oxide (PEO). In fact, while the understanding of the underlying mechanisms has greatly improved within recent years, it remains rather challenging to outperform PEO-based electrolyte systems. Nonetheless, it is not impossible, as highlighted by several examples mentioned herein, especially in consideration of the extremely rich polymer chemistry and with respect to the substantial progress already achieved in designing tailored molecules with well-defined nanostructures

    Single‐Ion Conducting Polymer Electrolyte for Superior Sodium‐Metal Batteries

    Get PDF
    Sodium-metal batteries (SMBs) are considered a potential alternative to high-energy lithium-metal batteries (LMBs). However, the high reactivity of metallic sodium towards common liquid organic electrolytes renders such battery technology particularly challenging. Herein, we propose a multi-block single-ion conducting polymer electrolyte (SIPE) doped with ethylene carbonate as suitable electrolyte system for SMBs. This novel SIPE provides a very high ionic conductivity (2.6 mS cm1^{−1}) and an electrochemical stability window of about 4.1 V at 40 °C, enabling stable sodium stripping and plating and excellent rate capability of Na | | Na3_3V2_2(PO4_4)3_3 cells up to 2 C. Remarkably, such cells provide a capacity retention of about 85 % after 1,000 cycles at 0.2 C thanks to the very high Coulombic efficiency (99.9 %), resulting from an excellent interfacial stability towards sodium metal and the Na3_3V2_2(PO4_4)3_3 cathode

    A beneficial combination of formic acid as a processing additive and fluoroethylene carbonate as an electrolyte additive for Li4_{4}Ti5_{5}O12_{12} lithium-ion anodes

    Get PDF
    The aqueous processing of lithium transition metal oxide active materials such as Li4_{4}Ti5_{5}O12_{12} (LTO) into electrodes remains a challenge owing to the high reactivity of such materials in contact with water, resulting in a rapid pH increase, aluminum current collector corrosion, and inferior cycling stability. Herein, the addition of formic acid (FA) as an electrode slurry processing additive is investigated, including a variation of the mixing speed as an additional important parameter. Following the identification of suitable electrode preparation conditions, the effect of fluoroethylene carbonate (FEC) as an electrolyte additive is studied in half-cells and full-cells comprising a LiNi0.5_{0.5}Mn0.3_{0.3}Co0.2_{0.2}O2_{2} (NMC532_{532}) based positive electrode. Owing to the beneficial impact of FEC on the solid electrolyte interphase (SEI) formed at the LTO|electrolyte interface, involving specifically the suppression of lithium salt decomposition, both the half-cells and the LTO‖NMC532_{532} full-cells exhibit a superior performance, achieving a capacity retention of 84.3% and 64.1% after 5000 and 10 000 cycles at 2C, respectively
    corecore