3D macroporous electrode and high-performance in lithium-ion batteries using SnO2 coated on Cu foam

A three-dimensional porous architecture makes an attractive electrode structure, as it has an intrinsic structural integrity and an ability to buffer stress in lithium-ion batteries caused by the large volume changes in high-capacity anode materials during cycling. Here we report the first demonstration of a SnO2-coated macroporous Cu foam anode by employing a facile and scalable combination of directional freeze-casting and sol-gel coating processes. The three-dimensional interconnected anode is composed of aligned microscale channels separated by SnO2 coated Cu walls and much finer micrometer pores, adding to surface area and providing space for volume expansion of SnO2 coating layer. With this anode, we achieve a high reversible capacity of 750 mAh g(-1) at current rate of 0.5 C after 50 cycles and an excellent rate capability of 590 mAh g(-1) at 2 C, which is close to the best performance of Sn-based nanoscale material so far.