The present disclosure relates to electroactive materials for use in electrodes of lithium-ion electrochemical cells and methods of making the same, for example, methods for lithiating electroactive materials. A method of lithiating an electroactive material may include dispersing an electroactive material precursor within a room-temperature electrolyte that includes a lithium-based salt and contacting the electrolyte mixture and a lithium source so as to cause the lithium source to ionize and form lithium ions. The lithium ions may react with the electroactive material precursor to form a fully lithiated electroactive material (e.g., greater than 70% of total lithiation). The method further includes, in certain aspects, electrochemically discharging the fully lithiated electroactive material to form a lithiated electroactive material having an optimized lithiation state (e.g., less than or equal to about 40% of a first lithiation state of the fully lithiated electroactive material).