During the past few years, with the increasing power demand generated by applications from portable devices to electric vehicles, more and more emphasis is put on manufacturing high energy and power density Li-ion batteries, i.e., to maximize the capacities while retaining a high rate capability. So far, the studies have been mainly dedicated to the development of powder type electrode materials and relatively little attention has been paid to studies of other electrode architectures. While composite electrodes containing a mixture of the active material powders, binders and conductive additives still are commonly used, such electrodes often yield poor material utilization, undefined material/component arrangements and a lot of complex interfaces. In the present work, we demonstrate that various highly ordered, free-standing oxide nanotube array electrodes, fabricated by electrochemical anodization approaches, can be used either for high energy density and power density Li-ion microbattery applications or as model monolithic electrodes for electrode engineering studies. By using anatase TiO2 nanotube electrodes (as an example of an intercalation type material), an areal capacity of 0.37 mAh cm-2 (i.e., 40 mAh g-1) at a rate of 10C (using a (dis-)charge  current density of 9 mA cm-2), and 1 mAh cm-2 (i.e., 91 mAh g-1) at a rate of C/5), can be achieved. [1] Well-defined monolithic anatase TiO2 nanotube electrodes with fine-tuned nanotube size gradients (including tube length, diameter and wall thickness) can also be manufactured using a bipolar electrochemistry approach. [2] The gradient nanotube electrodes can provide excellent rate performance, with capacities from of 0.16 mAh cm-2 or 169 mAh g-1 at a rate of C/5 to 0.04 mAh cm-2 or 42 mAh g-1 at a rate of 50C. In addition, free-standing Nb2O5 nanotube electrodes, which can be cycled for 10000 cycles with only a 20% loss of initial capacities, can provide unprecedented high-rate battery performances, i.e. the capacities from of 0.1 mAh cm-2 or 110 mAh g-1 at a rate of C/5 to 0.04 mAh cm-2 or 44 mAh g-1at a rate of 100C.[3] Some recent work carried out to investigate highly ordered Fe3O4 nanotubular/nanoporous electrodes as a prototype free-standing conversion electrode will also be described.  References:[1] W. Wei, et al.,  submitted, 2015 ; [2]  W. Wei, et al., Electrochim. Acta 2015, 176, 1393 ; [3] W. Wei, et al.,  in preparation, 2016