@article{hung_modeling_2025,

title = {Modeling Structured Electrodes and Graded Porosity for Improving Discharge Rate Capability in Ultra-Thick Graphite|LiNi0.6Mn0.2Co0.2O2 Batteries},

author = {Chih-Hsuan Hung and Srikanth Allu and Corie L. Cobb},

url = {https://dx.doi.org/10.1149/1945-7111/ada4e0},

doi = {10.1149/1945-7111/ada4e0},

issn = {1945-7111},

year  = {2025},

date = {2025-01-01},

urldate = {2025-01-01},

journal = {Journal of The Electrochemical Society},

volume = {172},

number = {1},

pages = {010513},

abstract = {Long-range electric vehicles (EVs) require high-energy-density batteries that also meet the power demands of high current charge and discharge. Ultra-thick (>100 μm) Lithium-ion battery electrodes are critical to enable this need, but slow ion transport in conventional uniform electrodes (UEs) reduces battery capacity at increasing charge/discharge rates. We present a 3D computational analysis on the impact of structured electrode (SE) and graded electrode (GE) geometries on the discharge rate capability of ultra-thick graphitetextbarLiNi0.6Mn0.2Co0.2O2 (NMC-622) battery cells based on the footprint of a commercial EV pouch cell. SE cathodes with either a “grid” or “line” geometry and GEs with two layers of porosity were modeled. Based on the results of 230 models, we found that the electrolyte volume fraction is a key parameter that impacts capacity improvements in UEs, GEs, and SEs at 2 C–6 C discharge rates. SEs have the greatest discharge rate capability, outperforming GEs and UEs due to reduced Lithium-ion concentration gradients across the electrode thickness, which mitigates electrolyte depletion at high rates. The best SE model has a “grid” geometry with gravimetric and volumetric energy density improvements of 0.9%–4% at C/2–2 C and 18%–24% at 4 C–6 C relative to UEs.},

note = {Publisher: IOP Publishing},

keywords = {batteries, battery modeling},

pubstate = {published},

tppubtype = {article}

}

@article{xiao_assessing_2024,

title = {Assessing cathode–electrolyte interphases in batteries},

author = {Jie Xiao and Nicole Adelstein and Yujing Bi and Wenjuan Bian and Jordi Cabana and Corie L. Cobb and Yi Cui and Shen J. Dillon and Marca M. Doeff and Saiful M. Islam and Kevin Leung and Mengya Li and Feng Lin and Jun Liu and Hongmei Luo and Amy C. Marschilok and Ying Shirley Meng and Yue Qi and Ritu Sahore and Kayla G. Sprenger and Robert C. Tenent and Michael F. Toney and Wei Tong and Liwen F. Wan and Chongmin Wang and Stephen E. Weitzner and Bingbin Wu and Yaobin Xu},

url = {https://www.nature.com/articles/s41560-024-01639-y},

doi = {10.1038/s41560-024-01639-y},

issn = {2058-7546},

year  = {2024},

date = {2024-10-07},

urldate = {2024-10-07},

journal = {Nature Energy},

pages = {1–11},

abstract = {The cathode–electrolyte interphase plays a pivotal role in determining the usable capacity and cycling stability of electrochemical cells, yet it is overshadowed by its counterpart, the solid–electrolyte interphase. This is primarily due to the prevalence of side reactions, particularly at low potentials on the negative electrode, especially in state-of-the-art Li-ion batteries where the charge cutoff voltage is limited. However, as the quest for high-energy battery technologies intensifies, there is a pressing need to advance the study of cathode–electrolyte interphase properties. Here, we present a comprehensive approach to analyse the cathode–electrolyte interphase in battery systems. We underscore the importance of employing model cathode materials and coin cell protocols to establish baseline performance. Additionally, we delve into the factors behind the inconsistent and occasionally controversial findings related to the cathode–electrolyte interphase. We also address the challenges and opportunities in characterizing and simulating the cathode–electrolyte interphase, offering potential solutions to enhance its relevance to real-world applications.},

note = {Publisher: Nature Publishing Group},

keywords = {batteries},

pubstate = {published},

tppubtype = {article}

}

@article{katz_high-viscosity_2024,

title = {High-Viscosity Phase Inversion Separators for Freestanding and Direct-on-Electrode Manufacturing in Lithium-Ion Batteries},

author = {Michelle E. R. Katz and Corie L. Cobb},

url = {https://doi.org/10.1021/acsami.4c09342},

doi = {10.1021/acsami.4c09342},

issn = {1944-8244},

year  = {2024},

date = {2024-08-28},

urldate = {2024-08-28},

journal = {ACS Applied Materials & Interfaces},

volume = {16},

number = {34},

pages = {44863–44878},

abstract = {Separators play a critical role in lithium-ion batteries (LIBs) by facilitating lithium-ion (Li-ion) transport while enabling safe battery operation. However, commercial separators made from polypropylene (PP) or polyethylene (PE) impose a discrete processing step in current LIB manufacturing as they cannot be manufactured with the same slot-die coating process used to fabricate the electrodes. Moreover, commercial separators cannot accommodate newer manufacturing processes used to produce leading-edge microbatteries and flexible batteries with customized form factors. As a path toward rethinking LIB fabrication, we have developed a high-viscosity polymer composite separator slurry that enables the fabrication of both freestanding and direct-on-electrode films. A streamlined phase inversion process is used to impart porosity in cast separator films upon drying. To understand the impacts of material composition and rheology on phase inversion processing and separator performance, we investigated four different separator formulations. We used either diethylene glycol (DEG) or triethyl phosphate (TEP) as a nonsolvent, and either silica (SiO2) or alumina (Al2O3) as an inorganic additive in a polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix. Through a down-selection process, we developed a TEP-SiO2 separator formulation that matched or outperformed a commercial Celgard 2325 (PP/PE/PP) separator and a Beyond Battery ceramic-coated PE (CC/PE/CC) separator under rate and cycle life tests in LiFePO4textbarLi4Ti5O12 (LFPtextbarLTO) and LiNi0.5Mn0.3Co0.2O2textbargraphite (NMC-532textbargraphite) coin cells at C/10–1C rates. Our TEP-SiO2 slurry had a viscosity of 298 Pa s at a 1 s–1 shear rate and shear-thinning behavior. When deposited directly onto an LTO anode and cycled against an LFP cathode, the direct-on-electrode TEP-SiO2 separator increased the specific capacity by 58% and 304% at 2C rates relative to the PP/PE/PP and CC/PE/CC separators, respectively. Additionally, the freestanding TEP-SiO2 separator maintained dimensional stability when heated to 200 °C for 1 h and demonstrated a higher elastic modulus and hardness than the PP/PE/PP and CC/PE/CC separators when measured with nanoindentation.},

note = {Publisher: American Chemical Society},

keywords = {additive manufacturing, batteries, printed batteries},

pubstate = {published},

tppubtype = {article}

}

@article{hatzell_challenges_2020,

title = {Challenges in lithium metal anodes for solid state batteries},

author = { Kelsey B. Hatzell and Xi Chelsea Chen and Corie L. Cobb and Neil P Dasgupta and Marm B. Dixit and Lauren E Marbella and Matthew T. McDowell and Partha Mukherjee and Ankit Verma and Venkatasubramanian Viswanathan and Andrew Westover and Wolfgang G. Zeier},

url = {https://doi.org/10.1021/acsenergylett.9b02668},

doi = {10.1021/acsenergylett.9b02668},

year  = {2020},

date = {2020-02-18},

urldate = {2020-02-18},

journal = {ACS Energy Letters},

volume = {5},

number = {3},

pages = {922-934},

abstract = {In this perspective, we highlight recent progress and challenges related to the integration of lithium metal anodes in solid-state batteries. While prior reports have suggested that solid electrolytes may be impermeable to lithium metal, this hypothesis has been disproven under a variety of electrolyte compositions and cycling conditions. Herein, we describe the mechanistic origins and importance of lithium filament growth and interphase formation in inorganic and organic solid electrolytes. Multi-modal techniques that combine real and reciprocal space imaging and modeling will be necessary to fully understand non-equilibrium dynamics at these buried interfaces. Currently, most studies on lithium electrode kinetics at solid electrolyte interfaces are completed in symmetric Li-Li configurations. To fully understand the challenges and opportunities afforded by Li metal anodes, full-cell experiments are necessary. Finally, the impacts of operating conditions on solid state batteries are largely unknown with respect to pressure, geometry, and break-in protocols. Given the rapid growth of this community and diverse portfolio of solid electrolytes, we highlight the need for detailed reporting of experimental conditions and standardization of protocols across the community.},

keywords = {batteries},

pubstate = {published},

tppubtype = {article}

}

@article{hung_computational_2025,

title = {Computational Analysis of Anode and Cathode Structuring Effects on Charge and Discharge in GraphitetextbarLiNi0.6Mn0.2Co0.2O2 Batteries},

author = {Chih-Hsuan Hung and Srikanth Allu and Corie L. Cobb},

url = {http://iopscience.iop.org/article/10.1149/1945-7111/ae0071},

doi = {10.1149/1945-7111/ae0071},

issn = {1945-7111},

journal = {Journal of The Electrochemical Society},

abstract = {Structured electrodes (SEs) improve the rate capability of Lithium-ion batteries by engineering micrometer-scale electrolyte regions into the electrode, promoting rapid ionic transport. Prior research has focused on structuring one electrode (anode or cathode) with an analysis on either the charge or discharge performance. We present a holistic study using three-dimensional models to investigate the isolated effects of structuring either electrode and the combined effects of structuring both electrodes on the charge and discharge capacity of single-layer cells at 4C and 6C. Volumetric and gravimetric discharge energy density (Wh/Lstack and Wh/kgstack) and charge capacity (Ah/kgstack and Ah/Lstack) are evaluated for multi-layer pouch cell stacks. Pairing SE anodes with SE cathodes demonstrated improvements up to 15% in discharge Wh/kgstack and up to 33% in charge Ah/kgstack over a conventional cell; Energy required to charge per Ah/kgstack was improved by 13% –14%. SE cathodes paired with a conventional anode exhibited improvements of 0.3% – 22% across all performance metrics evaluated. Conversely, pairing a SE anode with a conventional cathode demonstrated improved charge capacity up to 13% but showed a 2% – 23% lower discharge energy density. The importance of aligning SEs in a cell from a performance and manufacturing perspective is also analyzed.},

keywords = {architected materials, batteries, battery modeling},

pubstate = {forthcoming},

tppubtype = {article}

}