Increasing the thickness of a battery electrode without comprising cell electrochemical performance, such as power density and cycling stability, is very challenging. In this work, we demonstrate the utility of 3D (three dimensional) Cu foam framework as a current collector for building carbon negative electrodes as thick as 1.2mm. When tested in a bipolar configuration, electrodes of 1.2 and 0.6mm thick delivered capacities of over 350mAhg−1 (>95% of theoretical capacity) up to a C/5 rate. We have also assembled a full cell composed of a 1.2mm thick negative electrode with Cu foam as the current collector and a 1.2mm thick L333 (LiNi1/3Mn1/3Co1/3O2) positive electrode with Al foam as the current collector. The cell exhibited good capacity retention at low rates. These results underscore the promise of 3D foam structures in terms of enabling ultra-thick electrodes for high energy density battery applications.