Fundamentals of Energy Conversion Processes
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Significant Extension of Zinc Battery Lifespan
Caroline Zörlein2024-10-29T09:59:12+01:00Oct 29, 2024|
TUM Researchers Develop New Chemical Method for Improved Energy Storage.
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Caroline Zörlein2024-10-28T10:45:40+01:00Oct 28, 2024|
The first Science Slam of Munich's excellence clusters.
Garching research campus attracts thousands of visitors
Caroline Zörlein2024-10-23T11:51:29+02:00Oct 23, 2024|
Highlights from the open day at the e-conversion booth.
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Highlights
Recent Publications
Q Yu, W Sun, S Wang, Q Qiu, W Zhang, H Tian, L Xia, P Müller-Buschbaum
Smart Electrolytes for Lithium Batteries with Reversible Thermal Protection at High Temperatures Journal Article
In: Batteries & Supercaps, vol. n/a, no. n/a, pp. e202400339, 2024.
@article{nokey,
title = {Smart Electrolytes for Lithium Batteries with Reversible Thermal Protection at High Temperatures},
author = {Q Yu and W Sun and S Wang and Q Qiu and W Zhang and H Tian and L Xia and P M\"{u}ller-Buschbaum},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/batt.202400339},
doi = {https://doi.org/10.1002/batt.202400339},
year = {2024},
date = {2024-06-19},
journal = {Batteries \& Supercaps},
volume = {n/a},
number = {n/a},
pages = {e202400339},
abstract = {Abstract Battery safety is a multifaceted concern, with thermal runaway standing out as a primary issue. In this work, we introduce a novel temperature-responsive, self-protection electrolyte governed by the phase separation dynamics of poly (butyl methacrylate) (PBMA) in lithium salt/tetraglyme (G4) blends. This innovation effectively mitigates the risks associated with thermal runaway in lithium batteries. Our electrolyte exhibits a temperature-responsive-recovery characteristic, imparting intelligent capabilities to lithium batteries. At temperatures of \>105 °C, the electrolyte transitions from a homogeneous phase to a segregated state, comprising a PBMA-rich phase with low conductivity and a high conductivity phase containing dissolved lithium salt in G4. The deposition of the PBMA-rich phase on the electrode surface obstructs the ion transport, thereby averting a thermal runaway. Subsequently, upon returning to room temperature of 25 °C, the electrolyte reverts to its homogeneous, highly conductive state, with battery capacity resuming at approximately 94 %. Thus, our electrolyte offers a robust, reversible, smart self-protection for batteries. Additionally, it demonstrates exceptional cycling performance at room temperature. Our findings open new avenues for thermo-reversible and self-protective electrolytes, advancing the safe and widespread adoption of lithium-ion batteries.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
H Zhu, Q Wang, W Chen, K Sun, H Zhong, T Ye, Z Wang, W Zhang, P Müller-Buschbaum, X W Sun, D Wu, K Wang
Chiral perovskite-CdSe/ZnS QDs composites with high circularly polarized luminescence performance achieved through additive-solvent engineering Journal Article
In: The Journal of Chemical Physics, vol. 160, no. 23, 2024, ISSN: 0021-9606.
@article{nokey,
title = {Chiral perovskite-CdSe/ZnS QDs composites with high circularly polarized luminescence performance achieved through additive-solvent engineering},
author = {H Zhu and Q Wang and W Chen and K Sun and H Zhong and T Ye and Z Wang and W Zhang and P M\"{u}ller-Buschbaum and X W Sun and D Wu and K Wang},
url = {https://doi.org/10.1063/5.0200692},
doi = {10.1063/5.0200692},
issn = {0021-9606},
year = {2024},
date = {2024-06-17},
journal = {The Journal of Chemical Physics},
volume = {160},
number = {23},
abstract = {Chiral perovskite materials are being extensively studied as one of the most promising candidates for circularly polarized luminescence (CPL)-related applications. Balancing chirality and photoluminescence (PL) properties is of great importance for enhancing the value of the dissymmetry factor (glum), and a higher glum value indicates better CPL. Chiral perovskite/quantum dot (QD) composites emerge as an effective strategy for overcoming the dilemma that achieving strong chirality and PL in chiral perovskite while at the same time achieving high glum in this composite is very crucial. Here, we choose diphenyl sulfoxide (DPSO) as an additive in the precursor solution of chiral perovskite to regulate the lattice distortion. How structural variation affects the chiral optoelectronic properties of the chiral perovskite has been further investigated. We find that chiral perovskite/CdSe\textendashZnS QD composites with strong CPL have been achieved, and the calculated maximum |glum| of the composites increased over one order of magnitude after solvent-additive modulation (1.55 × 10−3 for R-DMF/QDs, 1.58 × 10−2 for R-NMP-DPSO/QDs, −2.63 × 10−3 for S-DMF/QDs, and −2.65 × 10−2 for S-NMP-DPSO/QDs), even at room temperature. Our findings suggest that solvent-additive modulation can effectively regulate the lattice distortion of chiral perovskite, enhancing the value of glum for chiral perovskite/CdSe\textendashZnS QD composites.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
L Grunenberg, C Keßler, T W Teh, R Schuldt, F Heck, J Kästner, J Groß, N Hansen, B V Lotsch
Probing Self-Diffusion of Guest Molecules in a Covalent Organic Framework: Simulation and Experiment Journal Article
In: ACS Nano, vol. 18, no. 25, pp. 16091-16100, 2024, ISSN: 1936-0851.
@article{nokey,
title = {Probing Self-Diffusion of Guest Molecules in a Covalent Organic Framework: Simulation and Experiment},
author = {L Grunenberg and C Ke\ssler and T W Teh and R Schuldt and F Heck and J K\"{a}stner and J Gro\ss and N Hansen and B V Lotsch},
url = {https://doi.org/10.1021/acsnano.3c12167},
doi = {10.1021/acsnano.3c12167},
issn = {1936-0851},
year = {2024},
date = {2024-06-11},
journal = {ACS Nano},
volume = {18},
number = {25},
pages = {16091-16100},
abstract = {Covalent organic frameworks (COFs) are a class of porous materials whose sorption properties have so far been studied primarily by physisorption. Quantifying the self-diffusion of guest molecules inside their nanometer-sized pores allows for a better understanding of confinement effects or transport limitations and is thus essential for various applications ranging from molecular separation to catalysis. Using a combination of pulsed field gradient nuclear magnetic resonance measurements and molecular dynamics simulations, we have studied the self-diffusion of acetonitrile and chloroform in the 1D pore channels of two imine-linked COFs (PI-3-COF) with different levels of crystallinity and porosity. The higher crystallinity and porosity sample exhibited anisotropic diffusion for MeCN parallel to the pore direction, with a diffusion coefficient of Dpar = 6.1(3) × 10\textendash10 m2 s\textendash1 at 300 K, indicating 1D transport and a 7.4-fold reduction in self-diffusion compared to the bulk liquid. This finding aligns with molecular dynamics simulations predicting 5.4-fold reduction, assuming an offset-stacked COF layer arrangement. In the low-porosity sample, more frequent diffusion barriers result in isotropic, yet significantly reduced diffusivities (DB = 1.4(1) × 10\textendash11 m2 s\textendash1). Diffusion coefficients for chloroform at 300 K in the pores of the high- (Dpar = 1.1(2) × 10\textendash10 m2 s\textendash1) and low-porosity (DB = 4.5(1) × 10\textendash12 m2 s\textendash1) samples reproduce these trends. Our multimodal study thus highlights the significant influence of real structure effects such as stacking faults and grain boundaries on the long-range diffusivity of molecular guest species while suggesting efficient intracrystalline transport at short diffusion times.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}