Lithiation/Delithiation Performance of Cu[sub 6]Sn[sub 5] with Carbon Paper as Current Collector

Lithiation/delithiation of both electrochemically and mechanochemically prepared on a carbon paper (CP) current collector was investigated by repeated galvanostatic cycles with time-limited charges to insert different amounts of lithium per Sn atom (Li/Sn) into the alloy. The results demonstrated that, unlike electrodeposited on Cu foil, both electrochemical and mechanochemical on CP can undergo hundreds of lithiation/delithiation cycles with at high current density (0.74 mA cm −2 ), thereby delivering constant amounts of charge with coulombic efficiency near 100%. The electrodes with a loading of 6.6 mg cm −2 and charge limited to 2.43 Li/Sn yielded a specific capacity of 330 mAh g −1 and a capacity per geometric area of 2.18 mAh cm −2 . These values compare well with those of graphite-based anodes of commercial batteries. The significant improvement in cyclability performance of the electrodes is due to the CP current collector's three-dimensional conductive matrix, which preserves the electric contact over cycling so that alloy cracking becomes less detrimental for the electric contact.