scispace - formally typeset
Search or ask a question
Author

Sebastian Maletti

Bio: Sebastian Maletti is an academic researcher from Leibniz Association. The author has contributed to research in topics: Battery (electricity) & Anode. The author has an hindex of 7, co-authored 18 publications receiving 84 citations. Previous affiliations of Sebastian Maletti include Dresden University of Technology & Karlsruhe Institute of Technology.

Papers
More filters
Journal ArticleDOI
TL;DR: O3-type layered NaNi 0.5Ti0.5O2, which has been reported previously as a promising cathode material for Na-ion batter-ies, has been characterized using comprehensive operando techniques combined with electrochemical and magnetiza-tion measurements, yielding a lower paramagnetic moment in the charged state.
Abstract: O3-type layered NaNi0.5Ti0.5O2, which has been reported previously as a promising cathode material for Na-ion batteries, has been characterized using comprehensive operando techniques combined with electrochemical and magnetization measurements. Operando Synchrotron diffraction revealed a reversible O3-P3 transformation during charge and discharge without any intermediate phases, which stands in contrast to NaNiO2 and NaNi0.5Mn0.5O2. Operando X-ray absorption studies showed that the electrochemical process in the potential window of 1.5-4.2 V vs Na+/Na is sustained exclusively by Ni oxidation and reduction while Ti remains inactive. These findings are further supported by ex situ magnetization measurements, yielding a lower paramagnetic moment in the charged state in agreement with Ni oxidation. On the basis of these insights, we elaborate on the beneficial stabilizing effect of Ti. However, a strong C-rate dependence for NaNi0.5Ti0.5O2 and NaNi0.5Mn0.5O2 during cycling known from the literature points at a rather high influence of the original structure stacking and the associated Na migration paths.

22 citations

Journal ArticleDOI
18 Feb 2020
TL;DR: The commercial development of high-energy lithium-sulfur (Li-S) batteries is still hampered by the irreversible active material loss and fast capacity decay triggered by the dissolution of polysulf... as discussed by the authors.
Abstract: The commercial development of high-energy lithium–sulfur (Li–S) batteries is still hampered by the irreversible active material loss and fast capacity decay triggered by the dissolution of polysulf...

21 citations


Cited by
More filters
01 Jan 2013
TL;DR: Structurally related Li₂Ru(1-y)Sn(y)O₃ materials that have a single redox cation and exhibit sustainable reversible capacities as high as 230 mA h g(-1) and unambiguously show that the reactivity of these high-capacity materials towards Li entails cumulative cationic and anionic reversible redox processes.
Abstract: Li-ion batteries have contributed to the commercial success of portable electronics and may soon dominate the electric transportation market provided that major scientific advances including new materials and concepts are developed. Classical positive electrodes for Li-ion technology operate mainly through an insertion–deinsertion redox process involving cationic species. However, this mechanism is insufficient to account for the high capacities exhibited by the new generation of Li-rich (Li1CxNiyCozMn(1

175 citations

01 Apr 2014
TL;DR: In this article, a P2-type Na 2/3 [Ni 1/3 Mn 2 /3 ]O 2 cathode material has been synthesized via spray drying method and a two-step solid state process.
Abstract: Abstract P2-type Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 cathode material has been synthesized via spray drying method and a two step solid state process. Electrochemical behavior of the prepared material as cathode material for sodium ion battery was investigated in different charge-discharge voltage ranges. The results indicated that the cycling performance of the P2-Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 cathode greatly depended on the voltage window. The material showed excellent reversibility between 2.0 V and 4.0 V with reversible capacity of 86 mAh g −1 (0.1 C) and 77 mAh g −1 (1 C). XRD analyses indicated that crystal structure of the P2-type Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 could be well maintained after long term cycling in 2.0–4.0 V. When the upper limiting voltage was increased to 4.5 V, the crystal structure of P2-Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 was irreversibly damaged due to over extraction of Na + in 4.0–4.5 V. On the other hand, when the cycling voltage range was between 1.6 V and 3.8 V, the discharge capacities increased to 135 mAh g −1 (0.1 C) and 108 mAh g −1 (1 C), respectively. However, the cycling stability in 1.6–3.8 V was not as excellent as that in 2.0–4.0 V. This maybe due to the lattice stress caused by the over insertion of Na + in the structure at lower voltage.

150 citations

Journal ArticleDOI
TL;DR: Li-S separators have attracted considerable attention due to their advantages, such as high specific capacity, high energy density, environmental friendliness, and low cost as mentioned in this paper, but the practical application of Li-S batteries is limited by some severe faults such as the dissolution and migration of polysulfides, the insulation and volume expansion during the cycling of elemental sulfur.

103 citations

01 Jan 2009
TL;DR: In this article, a quasi 6-day planetary wave oscillation was observed to occur in relation with planetary wave activity at Wuhan, China (30.6 degrees N, 114.5 degrees E).
Abstract: Quasi 6-day oscillations in E-s occurrence were observed to occur in relation with planetary wave activity at Wuhan, China (30.6 degrees N, 114.5 degrees E). Wavelet analysis of E-s occurrence time series revealed that a strong 5- to 7-day oscillation was present during the period from about day 120 to 137 of 2003. The same quasi 6-day planetary wave oscillation was also found to dominate the spectrum of concurrent wind data measured in the 80- to 100-km region by a meteor radar, in agreement with the E-s occurrence. There is also a great deal of similarity between the 5- to 7-day band-pass filtered waveforms of E-s occurrence and the wind data. By estimating the wave phase changes with attitude, the quasi 6-day PW in the zonal wind was found to be in phase with the sporadic E layer critical frequency, f(o)E(s), at about 115 km, close to the observed E-s height. The quasi 6-day PW modulation was also present in the amplitude of the 12-h and 24-h periodicities which existed in the f(o)E(s) time series. The present results provide new evidence in favor of a planetary wave indirect role on E-s formation through the modulation of tides, which in line with previous studies by Haldoupis and Pancheva (2002), and Pancheva et al. (2003).

98 citations

01 Sep 2017
TL;DR: In this paper, the de-solvation process and the transport of Li+ in the preformed solid electrolyte interphase (SEI) on electrodes until the Li+ accepts an electron at the electrode and becomes a Li in the electrode.
Abstract: Understanding the factors limiting Li+ charge transfer kinetics in Li-ion batteries is essential in improving the rate performance, especially at lower temperatures. The Li+ charge transfer process involved in the lithium intercalation of graphite anode includes the step of de-solvation of the solvated Li+ in the liquid electrolyte and the step of transport of Li+ in the preformed solid electrolyte interphase (SEI) on electrodes until the Li+ accepts an electron at the electrode and becomes a Li in the electrode. Whether the de-solvation process or the Li+ transport through the SEI is a limiting step depends on the nature of the interphases at the electrode and electrolyte interfaces. Several examples involving the electrode materials such as graphite, lithium titanate (LTO), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA) and solid Li+ conductor such as lithium lanthanum titanate or Li-Al-Ti-phosphate are reviewed and discussed to clarify the conditions at which either the de-solvation or the transport of Li+ in SEI is dominating and how the electrolyte components affect the activation energy of Li+ charge transfer kinetics. How the electrolyte additives impact the Li+ charge transfer kinetics at both the anode and the cathode has been examined at the same time in 3-electrode full cells. The resulting impact on Li+ charge transfer resistance, Rct, and activation energy, Ea, at both electrodes are reported and discussed.

66 citations