Effects of Substrate Morphology and Postelectrodeposition on Structure of Cu Foam and Their Application for Li-Ion Batteries

The effects of Cu substrate morphology and postelectrodeposition on the porosity and mechanical strength of Cu foam electrodeposits are examined. The porosity of the Cu foam is enhanced by changing the morphology of the Cu substrate from smooth to nodular because H-2 bubbles are split into small bubbles by the nodules. In addition, the adhesive properties of the Cu foam deposited on the nodular Cu foil are improved by the mechanical interlocking effects of the nodules. As a result of the postelectrodeposition treatment, the mechanical strength of the Cu foam is significantly enhanced primarily due to the covering of the post-Cu electrodeposit on the dendrite crystallites of the Cu foam. The Li capacity and cycle performances of a Sn anode are clearly improved when Sn is electrodeposited on the covered Cu foam on the nodular Cu foil compared with that on the uncovered Cu foam: 451 mAh g(-1) at the 30th cycle for the Sn anode formed on the covered Cu foam on a nodular Cu foil and 89 mAh g(-1) at the 30th cycle for the Sn electrode on the uncovered Cu foam on a smooth Cu foil.