Portions of the oxide layer are removed to substantially planarize the trench-filled oxide layer as the first polysilicon layer.

The trick is to put the titanium oxide in as a layer between the part of the cell where the electrons are liberated and the part where they are collected for dispatch into the wider world.

The lead plates collect a layer of very fine lead oxide that is often simply shaken off, freeing it to be inhaled or otherwise absorbed into the body.