A5025200601- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Extraction and Separation Processes
- Supercapacitor Materials and Fabrication
- Semiconductor materials and devices
- Electron and X-Ray Spectroscopy Techniques
- Advanced Battery Technologies Research
- MXene and MAX Phase Materials
- Digital Innovation in Industries
- Interconnection Networks and Systems
- Delphi Technique in Research
- Semiconductor materials and interfaces
- 2D Materials and Applications
- Recycling and Waste Management Techniques
- Advanced Electron Microscopy Techniques and Applications
- Innovation, Technology, and Society
University of Münster
2021-2024
Helmholtz-Institute Münster
2024
Saarland University
2022
Leibniz-Institute for New Materials
2022
The syntheses of Ni-poor (NCM111, LiNi1/3Co1/3Mn1/3O2) and Ni-rich (NCM811 LiNi0.8Co0.1Mn0.1O2) lithium transition-metal oxides (space group R3̅m) from hydroxide precursors (Ni1/3Co1/3Mn1/3(OH)2, Ni0.8Co0.1Mn0.1(OH)2) are investigated using in situ synchrotron powder diffraction near-edge X-ray absorption fine structure spectroscopy. development the layered these two cathode materials proceeds via utterly different reaction mechanisms. While synthesis NCM811 involves a rock salt-type...
Abstract The high-voltage oxygen redox activity of Li-rich layered oxides enables additional capacity beyond conventional transition metal (TM) contributions and drives the development positive electrode active materials in secondary Li-based batteries. However, often face voltage decay during battery operation. In particular, although with a high nickel content demonstrate improved stability, they suffer from poor discharge capacity. Here, via physicochemical electrochemical measurements,...
Bond formation and breakage is crucial upon energy storage in lithium transition metal oxides (Li Me O 2 , = Ni, Co, Mn), i.e. the conventional cathode materials Li ion batteries. Near-edge X-ray absorption finestructure spectroscopy (NEXAFS) of L K edge performed first discharge LiNi x Co (1−x)/2 Mn ( 0.33: NCM111, 0.6: NCM622, 0.8: NCM811) combination with charge transfer multiplet (CTM) calculations provide unambiguous evidence that redox reactions NCMs proceed via a reversible oxidation...
Abstract Direct recycling is a key technology for enabling circular economy of spent lithium ion batteries (LIBs). For cathode active materials (CAMs), it regarded as the tightest closed‐loop and most efficient approach among current techniques simply proceeds via re‐lithiation reconstruction aged CAMs instead separating them into elemental components. In this work, spent, i.e., morphologically structurally decomposed CAM based on LiNi 0.83 Co 0.12 Mn 0.05 O 2 (NCM‐831205) restored by...
Abstract Rechargeable lithium‐ion batteries (LIBs) are critical for enabling sustainable energy storage. The capacity of cathode materials is a major limiting factor in the LIB performance, and doping has emerged as an effective strategy enhancing electrochemical properties nickel‐rich layered oxides such NCM811. In this study, boron homogeneously incorporated into tetrahedral site NCM811 through co‐precipitation, leading to inductive effect on transition metal ( TM )‐O‐B bonds that delayed...
Reversible and irreversible charge exchange reactions of Li- Mn-rich layered oxides (Li1.15Ni0.2Co0.1Mn0.55O2, LLO) are investigated with bulk surface-sensitive near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at the Ni L2,3, Co Mn O K edges; mass spectrometry (MS); operando synchrotron powder diffraction (SXPD). The present work shows relation between O–O formation in Ni, Co, reduction/oxidation processes, which turn deliver outstanding capacities Li-rich (LLO). Moreover,...
Iron- and manganese-based layered electrodes for sodium-ion batteries have attracted renewed interest due to their low cost environmental friendliness. However, phase changes at high voltage the Jahn–Teller effect lead a short cycle life poor rate capability. Herein, we describe optimization of structure Co/Ni free Na2/3Mn1/2Fe1/2O2 cathode via partial substitution Fe by Mn Ti explore redox activity P2-type Mn/Fe-based cathodes. The obtained P2–Na2/3Mn7/12Fe1/3Ti1/12O2 (NMFTO) exhibits solid...
Li/Mn‐rich layered oxide (LMR) cathode active materials promise exceptionally high practical specific discharge capacity (>250 mAh g −1 ) as a result of both conventional cationic and anionic oxygen redox. The latter requires electrochemical activation at potential (>4.5 V vs Li|Li + ), though it is accompanied by voltage fade in the course continuous release lattice oxygen, layered‐to‐spinel phase transformation, redox couple shift, well transition metal dissolution, whereas...
Mixed-metal oxides (MMOx), with more than one (transition) metal, provide versatile structural and electrochemical properties well exploited in energy conversion storage. The preparation of MMOx from single-source precursors benefits homogeneous composition uniform metal distribution. Herein, we describe layered mixed-metal carbides (MXenes) as templates to prepare MMOx. Through thermal oxidation TiNb-based MXenes CO2, mixtures Ti Nb were produced. Ti-to-Nb ratio the MXene significantly...
Abstract The electrochemical performance of cathode materials in Li‐ion batteries is reflected macroscopic observables such as the capacity, voltage, and state charge (SOC). However, physical origin parameters are atomistic processes that scale up to a picture. Thus, revealing function failure devices requires multiscale (and ‐time) approach using spectroscopic microscopic techniques. In this work, we combine near‐edge X‐ray absorption fine structure spectroscopy (NEXAFS) determine chemical...
Lithium-Ion Batteries In article number 2400129, Johannes Kasnatscheew and co-workers show Li-ion-batteries with Li/Mn-rich cathodes, which have the potential to compete state-of-the-art cathodes. Their well-known dilemma of poor cycle life at high upper-cut voltages (UCVs) low specific energies UCVs can be reasonably compensated by adjusting voltage windows during formation post cycles, as investigated demonstrated for LMR || graphite cells.
Abstract Aus „Electrochemistry“ wurde in diesem Jahr „Electrochemistry Undercover“, eine aufgrund der Covid‐19‐Pandemie vollständig digitalisierte Konferenz. Wie Postersession dabei funktionieren könnte, haben Mitarbeitende des Meet‐Batterieforschungszentrums Münster überlegt und umgesetzt. Ihre Erfahrungen liefern Ideen für den wissenschaftlichen Austausch auf Distanz.
<title>Abstract</title> Rechargeable lithium-ion batteries (LIBs) are critical for enabling sustainable electrochemical energy storage. The capacity of cathode materials is a major limiting factor in the LIB performance, and doping has emerged as an effective strategy enhancing properties nickel-rich layered oxides such NCM811. In this study, boron was successfully incorporated onto tetrahedral site NCM811 through co-precipitation method using Couette-Taylor Flow Reactor (CTFR). outcome...
The synthesis of Ni-poor (NCM111, LiNi 1/3 Co Mn O 2 ) and Ni-rich (NCM811 0.8 0.1 lithium transition metal oxides (space group R-3m from hydroxide precursors (Ni (OH) , Ni are investigated with in situ synchrotron powder diffraction (SXPD) near edge x-ray absorption fine structure spectroscopy (NEXAFS). development the layered these two cathode materials proceeds via utterly different reaction mechanisms. While NCM811 involves a rock salt-type intermediate phase, NCM111 reveals throughout...
Ni-rich layered oxides (LiNi x Co y Mn z O 2 , x≥0.8, x+y+z=1) would fulfil the energy density requirements of automobile industry since they offer outstanding capacities at relatively high mean voltages and sufficient power densities 1-3 . However, materials still show significant capacity voltage fade which requires substantial research. Recently we have shown that electronic structure is key to understand performance but also failure 1 Thus, intend modify using anionic dopants such as...