Methods and reactors for electrochemically expanding a parent material and expanded parent materials are described. Current methods of expanding parent materials incompletely-expand parent material, requiring expensive and time-consuming separation of expanded parent material from unexpanded parent materials. This problem is addressed by the methods and reactor for electrochemically expanding a parent material described herein, which during operation maintain electrical connectivity between the parent material and an electrical power source. The resulting materials described herein have a greater proportion of expanded parent material relative to unexpanded parent material compared to those made according to others methods.