THREE-DIMENSIONAL BATTERIES WITH COMPRESSIBLE CATHODES

A secondary battery for cycling between a charged and a discharged state is provided. The secondary battery has an electrode assembly having a population of anode structures, a population of cathode structures, and an electrically insulating microporous separator material. The electrode assembly also has a set of electrode constraints that at least partially restrains growth of the electrode assembly. Members of the anode structure population have a first cross-sectional area, Awhen the secondary battery is in the charged state and a second cross-sectional area, A, when the secondary battery is in the discharged state, and members of the cathode structure population have a first cross-sectional area, Cwhen the secondary battery is in the charged state and a second cross-sectional area, C, when the secondary battery is in the discharged state, where Ais greater than A, and Cis less than C.