Electrochemical devices with multifunctional electrode separator assemblies having built-in reference electrodes

A motor vehicle, comprising:

• a vehicle body;
• a plurality of road wheels attached to the vehicle body;
• a traction motor attached to the vehicle body and operable to drive one or more of the road wheels to thereby propel the motor vehicle;
• and
• a traction battery pack attached to the vehicle body and operable to power the traction motor, the traction battery pack containing a plurality of lithium-class battery cells, each of the lithium-class battery cells including:
• a battery housing;
• an electrolyte enclosed inside the battery housing and configured to conduct ions;
• an electrode stack enclosed inside the battery housing in electrochemical contact with the electrolyte, the electrode stack including a first working electrode in spaced facing relation with a second working electrode;
• and
• an electrode separator assembly interposed between the first and second working electrodes, the electrode separator assembly including:
• a separator sheet formed with an electrically insulating material and including a reference electrode;
• a tab pocket integral with and projecting from an end of the separator sheet, the tab pocket defining therein a tab chamber with a chamber opening;
• and
• an electrode tab rigidly attached via an electrically conductive adhesive to the tab pocket and formed with an electrically conductive material, the electrode tab having a first end disposed in the tab chamber and a second end projecting out from the chamber opening.

A method of assembling an electrochemical device, the method comprising:

• receiving a device housing of the electrochemical device;
• locating an electrolyte inside the device housing, the electrolyte being configured to conduct ions;
• locating an electrode stack inside the device housing in electrochemical contact with the electrolyte, the electrode stack including first and second working electrodes;
• and
• locating an electrode separator assembly between the first and second working electrodes, the electrode separator assembly including:
• a separator sheet formed with an electrically insulating material and including a reference electrode;
• a tab pocket projecting from an end of the separator sheet and defining a tab chamber with a chamber opening;
• and
• an electrode tab attached to the tab pocket and formed with an electrically conductive material, the electrode tab having a first end disposed in the tab chamber and a second end projecting out from the chamber opening.