Prof. Dr. Jennifer Rupp
Academic Research Focus
- Solid state materials for sustainable energy storage and conversion
- Solid state batteries
- Redox flow batteries
- Solid oxide fuel cells
- Solid state batteries
- Redox flow batteries
- Solid oxide fuel cells
Fields of Application
Batteries, Fuel Cells, Semiconductor Materials, Solar Fuels
Publications
4.
L P Kong, P J Williams, F Brushett, J L M Rupp
Unveiling Coexisting Battery-Type and Pseudocapacitive Intercalation Mechanisms in Lithium Titanate Journal Article
In: Advanced Energy Materials, 2025, ISSN: 1614-6832.
@article{nokey,
title = {Unveiling Coexisting Battery-Type and Pseudocapacitive Intercalation Mechanisms in Lithium Titanate},
author = {L P Kong and P J Williams and F Brushett and J L M Rupp},
url = {\<Go to ISI\>://WOS:001544773300001},
doi = {10.1002/aenm.202503080},
issn = {1614-6832},
year = {2025},
date = {2025-08-06},
journal = {Advanced Energy Materials},
abstract = {Conventional lithium-ion (Li-ion) batteries and supercapacitors face inherent trade-offs between power and energy densities, restricting their adaptability in applications requiring dynamic performance across both regimes. Here, a "zero-strain" lithium titanate (Li4Ti5O12) as a new class of battery-capacitive material exhibiting dual lithiation mechanisms, combining diffusion-controlled battery-type redox reactions and surface-controlled pseudocapacitive intercalation, depending on the operating potential, is revealed. At approximate to 1.55 V (vs Li/Li+), lithium titanate undergoes a two-phase transition reaction between Li4Ti5O12 and Li7Ti5O12, involving Li migration between 8a and 16c Wyckoff sites. Upon deeper lithiation to potentials near 0 V, Li ions reoccupy the 8a sites, triggering a reversible pseudocapacitive response with fast kinetics. Leveraging these dual lithiation mechanisms, lithium titanate delivers a high reversible capacity of approximate to 215 mAh g-1 at 20 mA g-1, retaining 148 mAh g-1 at 2000 mA g-1. The high-rate capability and cycling stability are attributed to a unique structure with minimal lattice strain during Li-site occupation. This work presents the first clear demonstration of a unique dual-mode charge storage mechanism in lithium titanate, which can reversibly operate in either battery-type or pseudocapacitive regimes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Conventional lithium-ion (Li-ion) batteries and supercapacitors face inherent trade-offs between power and energy densities, restricting their adaptability in applications requiring dynamic performance across both regimes. Here, a "zero-strain" lithium titanate (Li4Ti5O12) as a new class of battery-capacitive material exhibiting dual lithiation mechanisms, combining diffusion-controlled battery-type redox reactions and surface-controlled pseudocapacitive intercalation, depending on the operating potential, is revealed. At approximate to 1.55 V (vs Li/Li+), lithium titanate undergoes a two-phase transition reaction between Li4Ti5O12 and Li7Ti5O12, involving Li migration between 8a and 16c Wyckoff sites. Upon deeper lithiation to potentials near 0 V, Li ions reoccupy the 8a sites, triggering a reversible pseudocapacitive response with fast kinetics. Leveraging these dual lithiation mechanisms, lithium titanate delivers a high reversible capacity of approximate to 215 mAh g-1 at 20 mA g-1, retaining 148 mAh g-1 at 2000 mA g-1. The high-rate capability and cycling stability are attributed to a unique structure with minimal lattice strain during Li-site occupation. This work presents the first clear demonstration of a unique dual-mode charge storage mechanism in lithium titanate, which can reversibly operate in either battery-type or pseudocapacitive regimes.
3.
M Munjal, T Prein, M M Ramadan, H B Smith, V Venugopal, J L M Rupp, I I Abate, E A Olivetti, K J Huang
Process cost analysis of performance challenges and their mitigations in sodium-ion battery cathode materials Journal Article
In: Joule, pp. 101871, 2025, ISSN: 2542-4351.
@article{nokey,
title = {Process cost analysis of performance challenges and their mitigations in sodium-ion battery cathode materials},
author = {M Munjal and T Prein and M M Ramadan and H B Smith and V Venugopal and J L M Rupp and I I Abate and E A Olivetti and K J Huang},
url = {https://www.sciencedirect.com/science/article/pii/S2542435125000522},
doi = {https://doi.org/10.1016/j.joule.2025.101871},
issn = {2542-4351},
year = {2025},
date = {2025-03-14},
journal = {Joule},
pages = {101871},
abstract = {Summary The success of sodium-ion batteries (SIBs) hinges on mitigating underperformance in ways that are cost effective, manufacturable, and scalable. This work investigates interfacial, morphological, and bulk interventions to enhance the performance of layered metal oxide cathode active materials (CAMs) for SIBs. We mapped the full space of literature-reported SIB CAM challenges and their mitigations. We then estimated the manufacturing costs for a diverse and representative set of mitigation approaches. Adding sacrificial salts can be cost effective, given low materials costs and minimal process changes. By contrast, many methods are reported to tune CAM morphology. Several are likely challenging at scale due to process throughput and yield limitations. Finally, bulk modifications can mitigate the moisture sensitivity of some CAMs, a likely less costly route than expanding stringent atmosphere controls during manufacturing. We end by discussing the limits and promise of process cost analysis, given the current state of battery reporting in the literature.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Summary The success of sodium-ion batteries (SIBs) hinges on mitigating underperformance in ways that are cost effective, manufacturable, and scalable. This work investigates interfacial, morphological, and bulk interventions to enhance the performance of layered metal oxide cathode active materials (CAMs) for SIBs. We mapped the full space of literature-reported SIB CAM challenges and their mitigations. We then estimated the manufacturing costs for a diverse and representative set of mitigation approaches. Adding sacrificial salts can be cost effective, given low materials costs and minimal process changes. By contrast, many methods are reported to tune CAM morphology. Several are likely challenging at scale due to process throughput and yield limitations. Finally, bulk modifications can mitigate the moisture sensitivity of some CAMs, a likely less costly route than expanding stringent atmosphere controls during manufacturing. We end by discussing the limits and promise of process cost analysis, given the current state of battery reporting in the literature.
2.
S C Sand, J L M Rupp, B Yildiz
A critical review on Li-ion transport, chemistry and structure of ceramic–polymer composite electrolytes for solid state batteries Journal Article
In: Chemical Society Reviews, vol. 54, no. 1, pp. 178-200, 2024, ISSN: 0306-0012.
@article{nokey,
title = {A critical review on Li-ion transport, chemistry and structure of ceramic\textendashpolymer composite electrolytes for solid state batteries},
author = {S C Sand and J L M Rupp and B Yildiz},
url = {http://dx.doi.org/10.1039/D4CS00214H},
doi = {10.1039/D4CS00214H},
issn = {0306-0012},
year = {2024},
date = {2024-11-18},
journal = {Chemical Society Reviews},
volume = {54},
number = {1},
pages = {178-200},
abstract = {In the transition to safer, more energy-dense solid state batteries, polymer\textendashceramic composite electrolytes may offer a potential route to achieve simultaneously high Li-ion conductivity and enhanced mechanical stability. Despite numerous studies on the polymer\textendashceramic composite electrolytes, disagreements persist on whether the polymer or the ceramic is positively impacted in their constituent ionic conductivity for such composite electrolytes, and even whether the interface is a blocking layer or a highly conductive lithium ion path. This lack of understanding limits the design of effective composite solid electrolytes. By thorough and critical analysis of the data collected in the field over the last three decades, we present arguments for lithium conduction through the bulk of the polymer, ceramic, or their interface. From this analysis, we can conclude that the unexpectedly high conductivity reported for some ceramic\textendashpolymer composites cannot be accounted for by the ceramic phase alone. There is evidence to support the theory that the Li-ion conductivity in the polymer phase increases along this interface in contact with the ceramic. The potential mechanisms for this include increased free volume, decreased crystallinity, and modulated Lewis acid\textendashbase effects in the polymer, with the former two to be the more likely mechanisms. Future work in this field requires understanding these factors more quantitatively, and tuning of the ceramic surface chemistry and morphology in order to obtain targeted structural modifications in the polymer phase.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the transition to safer, more energy-dense solid state batteries, polymer–ceramic composite electrolytes may offer a potential route to achieve simultaneously high Li-ion conductivity and enhanced mechanical stability. Despite numerous studies on the polymer–ceramic composite electrolytes, disagreements persist on whether the polymer or the ceramic is positively impacted in their constituent ionic conductivity for such composite electrolytes, and even whether the interface is a blocking layer or a highly conductive lithium ion path. This lack of understanding limits the design of effective composite solid electrolytes. By thorough and critical analysis of the data collected in the field over the last three decades, we present arguments for lithium conduction through the bulk of the polymer, ceramic, or their interface. From this analysis, we can conclude that the unexpectedly high conductivity reported for some ceramic–polymer composites cannot be accounted for by the ceramic phase alone. There is evidence to support the theory that the Li-ion conductivity in the polymer phase increases along this interface in contact with the ceramic. The potential mechanisms for this include increased free volume, decreased crystallinity, and modulated Lewis acid–base effects in the polymer, with the former two to be the more likely mechanisms. Future work in this field requires understanding these factors more quantitatively, and tuning of the ceramic surface chemistry and morphology in order to obtain targeted structural modifications in the polymer phase.
1.
W O’leary, M Grumet, W Kaiser, T Bučko, J L M Rupp, D A Egger
In: Journal of the American Chemical Society, vol. 146, no. 39, pp. 26863-26876, 2024, ISSN: 0002-7863.
@article{nokey,
title = {Rapid Characterization of Point Defects in Solid-State Ion Conductors Using Raman Spectroscopy, Machine-Learning Force Fields, and Atomic Raman Tensors},
author = {W O’leary and M Grumet and W Kaiser and T Bu\v{c}ko and J L M Rupp and D A Egger},
url = {https://doi.org/10.1021/jacs.4c07812},
doi = {10.1021/jacs.4c07812},
issn = {0002-7863},
year = {2024},
date = {2024-10-02},
journal = {Journal of the American Chemical Society},
volume = {146},
number = {39},
pages = {26863-26876},
abstract = {The successful design of solid-state photo- and electrochemical devices depends on the careful engineering of point defects in solid-state ion conductors. Characterization of point defects is critical to these efforts, but the best-developed techniques are difficult and time-consuming. Raman spectroscopy─with its exceptional speed, flexibility, and accessibility─is a promising alternative. Raman signatures arise from point defects due to local symmetry breaking and structural distortions. Unfortunately, the assignment of these signatures is often hampered by a shortage of reference compounds and corresponding reference spectra. This issue can be circumvented by calculation of defect-induced Raman signatures from first principles, but this is computationally demanding. Here, we introduce an efficient computational procedure for the prediction of point defect Raman signatures in solid-state ion conductors. Our method leverages machine-learning force fields and “atomic Raman tensors”, i.e., polarizability fluctuations due to motions of individual atoms. We find that our procedure reduces computational cost by up to 80% compared to existing first-principles frozen-phonon approaches. These efficiency gains enable synergistic computational\textendashexperimental investigations, in our case allowing us to precisely interpret the Raman spectra of Sr(Ti0.94Ni0.06)O3-δ, a model oxygen ion conductor. By predicting Raman signatures of specific point defects, we determine the nature of dominant defects and unravel impacts of temperature and quenching on in situ and ex situ Raman spectra. Specifically, our findings reveal the temperature-dependent distribution and association behavior of oxygen vacancies and nickel substitutional defects. Overall, our approach enables rapid Raman-based characterization of point defects to support defect engineering in novel solid-state ion conductors.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The successful design of solid-state photo- and electrochemical devices depends on the careful engineering of point defects in solid-state ion conductors. Characterization of point defects is critical to these efforts, but the best-developed techniques are difficult and time-consuming. Raman spectroscopy─with its exceptional speed, flexibility, and accessibility─is a promising alternative. Raman signatures arise from point defects due to local symmetry breaking and structural distortions. Unfortunately, the assignment of these signatures is often hampered by a shortage of reference compounds and corresponding reference spectra. This issue can be circumvented by calculation of defect-induced Raman signatures from first principles, but this is computationally demanding. Here, we introduce an efficient computational procedure for the prediction of point defect Raman signatures in solid-state ion conductors. Our method leverages machine-learning force fields and “atomic Raman tensors”, i.e., polarizability fluctuations due to motions of individual atoms. We find that our procedure reduces computational cost by up to 80% compared to existing first-principles frozen-phonon approaches. These efficiency gains enable synergistic computational–experimental investigations, in our case allowing us to precisely interpret the Raman spectra of Sr(Ti0.94Ni0.06)O3-δ, a model oxygen ion conductor. By predicting Raman signatures of specific point defects, we determine the nature of dominant defects and unravel impacts of temperature and quenching on in situ and ex situ Raman spectra. Specifically, our findings reveal the temperature-dependent distribution and association behavior of oxygen vacancies and nickel substitutional defects. Overall, our approach enables rapid Raman-based characterization of point defects to support defect engineering in novel solid-state ion conductors.