Dealloying-Derived Nanoporous Cu(6)Sn(5) Alloy as Stable Anode Materials for Lithium-Ion Batteries

The volume expansion during Li ion insertion/extraction remains an obstacle for the application of Sn-based anode in lithium ion-batteries. Herein, the nanoporous (np) Cu(6)Sn(5) alloy and Cu(6)Sn(5)/Sn composite were applied as a lithium-ion battery anode. The as-dealloyed np-Cu(6)Sn(5) has an ultrafine ligament size of 40 nm and a high BET-specific area of 15.9 m(2) g(−1). The anode shows an initial discharge capacity as high as 1200 mA h g(−1), and it remains a capacity of higher than 600 mA h g(−1) for the initial five cycles at 0.1 A g(−1). After 100 cycles, the anode maintains a stable capacity higher than 200 mA h g(−1) for at least 350 cycles, with outstanding Coulombic efficiency. The ex situ XRD patterns reveal the reverse phase transformation between Cu(6)Sn(5) and Li(2)CuSn. The Cu(6)Sn(5)/Sn composite presents a similar cycling performance with a slightly inferior rate performance compared to np-Cu(6)Sn(5). The study demonstrates that dealloyed nanoporous Cu(6)Sn(5) alloy could be a promising candidate for lithium-ion batteries.