Here's another quote in the article where they're speaking to the American Chemical Society....

"When the battery is used to power a car (discharge mode), lithium ions move out of the graphite anode and cross the electrolyte toward the cathode....lithium atoms that are intercalated in the graphite are oxidized at the anode, which leaves free electrons behind that can travel through an electric circuit.” An electrolyte, by the way, is a gel or liquid that can basically carry electric charge via ions. When the temperature is cold, these chemical reactions are slowed in both directions."