Whittingham proves rechargeable lithium can work

Working at Exxon during the 1970s oil crisis, M. Stanley Whittingham built a rechargeable cell with a titanium disulfide cathode and a metallic-lithium anode. The layered cathode allowed lithium ions to move into and out of its structure without destroying it, a reversible process known as intercalation. The cell delivered about two volts, unusually high for its time, and proved that lithium’s light weight and electrochemical potential could support compact energy storage. It was not yet a safe consumer battery: repeated charging could form needle-like lithium dendrites, creating internal short circuits and a risk of fire. The experiment nevertheless established the core ion-shuttling concept later designs would retain.