Li Reaction Behavior of GaP Nanoparticles Prepared by a Sodium Naphthalenide Reduction Method

Li reaction phenomena of GaP nanoparticles (<30 nm) prepared by a sodium naphthalenide reduction method at 390 °C in an autoclave were investigated using electrochemical, in (ex) situ X-ray diffraction (XRD), and X-ray absorption spectra (XAS) measurements between 1.5 and 0 V. During the first discharge reactions, lithium intercalated Li 2 GaP and irreversible Li n P 7 phases were formed. Li 2 GaP was only stable above 0.36 V after which it decomposed to Li x Ga and electrochemically inactive Li n P phases. Overall, the reversible capacity contribution (∼800 mAh/g) was from the reversible phase transformation between the Li x Ga and Ga phases.