phase does not form in silicon, including 50 mV, 8,69,72 60 mV, The biggest change in the amount of c-Li15Si4 and how long c-Li15Si4 formation persists, occurs between a 60 and 80 mV lithiation cut-off voltage (Figure ). The lower lithiation plateau of graphite is within the 60-80 mV vs. Li voltage interval, meaning that in graphite/Si blended electrodes, Si will be exposed to potentials that are right on the cusp of inducing formation of c-Li15Si4, depending on size. As suggested by Gao et al., c-Li15Si4 may be particularly reactive with the electrolyte, which should result in lower coulombic efficiency when larger amounts of c-Li15Si4 are formed. (2)