Quantifying the effect of electronic conductivity on the rate-performance of nanocomposite battery electrodes
Tian, Ruiyuan; Alcala, Nolito; O'Neill, Steven; Horvath, Dominik; Coelho, João; Griffin, Aideen; Zhang, Yan; Nicolosi, Valeria; O'Dwyer, Colm; Coleman, Jonathan
Date:
2020-01-30
Copyright:
© 2020, American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Energy Materials after technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acsaem.0c00034
Full text restriction information:
Access to this article is restricted until 12 months after publication by request of the publisher.
Restriction lift date:
2021-01-30
Citation:
Tian, R., Alcala, N., O'Neill, S., Horvath, D., Coelho, J., Griffin, A., Zhang, Y., Nicolosi, V., O'Dwyer, C. and Coleman, J. (2020) 'Quantifying the effect of electronic conductivity on the rate-performance of nanocomposite battery electrodes', ACS Applied Energy Materials, 3(3), pp. 2966-2974. doi: 10.1021/acsaem.0c00034
Abstract:
While it is well-known that the electronic conductivity of electrodes has a critical impact on rate performance in batteries, this relationship has been quantified only by computer simulations. Here we investigate the relationship between electrode electronic conductivity and rate performance in a model cathode system of lithium–nickel–manganese–cobalt–oxide (NMC) filled with various quantities of carbon black, single-walled carbon nanotubes, and graphene. We find extreme conductivity anisotropy and significant differences in the dependence of conductivity on mass fraction among the different fillers. Fitting capacity versus rate curves yielded the characteristic time associated with charge/discharge. This parameter increased linearly with the inverse of the out-of-plane electronic conductivity, with all data points falling on the same master curve. Using a simple mechanistic model for the characteristic time, we develop an equation that matches the experimental data almost perfectly with no adjustable parameters. This implies that increasing the electrode conductivity improves the rate performance by decreasing the RC charging time of the electrode and shows rate performance to be optimized for any electrode once σOOP > 1 S/m, a condition achieved by including <1 wt % single-walled carbon nanotubes in the electrode.
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