First Principles Modelling Insights into Lithium-Ion Battery Materials including Point Defects.

The traditional lithium-ion battery(LIB) anode is composed of graphite but recently silicon has been proposed as an alternative due to its ten-fold increase in theoretical capacity. Using AIRSS[1] we have predicted phases of lithium group 4, group 5 and group 6 compounds[2,3,4] finding many new phases. We calculate average voltages, capacities and chemical shielding and compare these with in situ and ex situ NMR and XRD experiments[4,5]. Point-defect impurities can dramatically alter the properties of these materials. I show how using the defect-AIRSS technique we can obtain an insight into such processes in LIB, presenting some impurities which mitigate[6,7] and some which augment a battery's function[5].\\ 1. C.J. Pickard, and R.J. Needs, Phys. Rev. Lett. 97, 045504 (2006).\\ 2. A. J. Morris, C. P. Grey, C. J. Pickard, Phys. Rev. B 90, 054111, (2014).\\ 3. C. George, A. J. Morris, M. H. Modarres and M. De Volder, Chem. Mater. 28, 7304-7310, (2016).\\ 4. K. A See, et al., J. Am. Chem. Soc. 136 , 16368-16377, (2014).\\ 5. M. Mayo, K. J. Griffith, et al., Chem. Mater. 28, 2011, (2016).\\ 6. A. J. Morris, R. J. Needs, E. Salager, C. P. Grey and C. J. Pickard, Phys. Rev. B 87, 174108, (2013).\\ 7. K. Ogata, et al. Nature Comm. 5, 3217 (2014).\\