Subassemblies for use in an electrochemical device are provided, as are processes for preparing the subassemblies and electrochemical cells incorporating the subassemblies. In some embodiments, the subassemblies include (a) a first electrode and (b) a separator or a first current collector or both. The first electrode is bonded to the separator or the first current collector or both. In some embodiments, the subassemblies further include a second electrode and a second current collector. In some embodiments, the electrodes or separators are sintered. Bipolar cells are also provided, including a plurality of stacked electrochemical cells that are joined in series. The positive electrode and the negative electrode of each stack include a sintered electrode.