Abstract
Increasing lithium-ion battery gravimetric energy density to > 300 Wh/kg, while simultaneously meeting a cost target of $80/kWh, is of paramount importance to increasing the driving range and affordability of electric vehicles. One way to address this goal is to reduce inactive components by increasing electrode areal capacities, but conventional thick electrode designs typically perform poorly at high discharge rates due to Li+ mass transport limitations. Here we compare the rate capability and cycle life of NMC 532/graphite pouch cells made with five different thick cathode and anode designs paired together in 25 combinations. We find that using different particle sizes to structure both the cathode and anode architectures in two-layer configurations results in a 2X capacity improvement over the worst-performing combination at high discharge rates (97 vs. 46 mAh/g at 2C). These different cathode/anode designs also translate to different cycle life performance, with many cells cycled at C/2 achieving ∼80% capacity retention after 1000 cycles, and cells cycled at 2C showing different degrees of capacity fade. Overall, these results demonstrate that simple, scalable changes in electrode design can significantly improve the performance of thick electrodes for high energy density batteries.
Original language | English |
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Article number | 230429 |
Journal | Journal of Power Sources |
Volume | 515 |
DOIs | |
State | Published - Dec 15 2021 |
Funding
This research at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy ( DOE ) under contract DE-AC05-00OR22725 , was sponsored by the Office of Energy Efficiency and Renewable Energy ( EERE ) Advanced Manufacturing Office ( AMO ) (Program Managers: David Hardy and Brian Valentine; Program Director Valri Lightner). We would like to thank Sergiy Kalnaus for his valuable discussions and input. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- Electrode architecture
- Li mass transport limitations
- Lithium-ion battery
- Pouch cell
- Thick electrode
- Two-layer electrode