A current collector assembly, such as for a bipolar lead acid battery, can include an electrically-conductive silicon substrate and a frame bonded to the electrically-conductive silicon substrate. The substrate can be treated or modified, such as to include one or more thin films which render a surface substrate electrically conductive and electrochemically stable in the presence of a lead acid electrolyte chemistry. An interface between the frame and the electrically-conductive silicon substrate can be hermetically sealed. In an example, the frame can provide an edge-seal ring configuration. In an example, a casing assembly can include a spacer bonded to the substrate, along with a casing segment and a thermally-conductive rib, the spacer isolating the thermally-conductive rib from the electrically-conductive silicon substrate electrically.