I was reading something today and they were talking about testing a half-cell battery. If we use lithium ion batteries as an example, looking at a graphite anode how would this cell be configured? I'm not sure how a battery can operate in this "half-cell" mode. Doesn't the battery need to be balanced? I suppose the source of lithium could be the electrolyte. Thanks for your help!

I am not quite sure about what you mean by half cell operation I mean for discharging you always need two terminals! and you need to connect the minus terminal to ground and you need a common ground for connection or your voltmeter cannot read a floating terminal. a voltmeter  has two terminals we are not dealing with coulombs!?