Characterization of bi-material electrodes for electrochemical hybrid energy storage devices

The hybridization of an electrochemical double layer capacitor and a lithium-ion battery at the electrode level can be realized by combining lithium insertion materials and capacitive materials in bi-material electrodes. A bi-material electrode based on activated carbon and LiMn2O4 has been prepared and characterized in the present work. An experimental setup was developed in order to measure the current sharing between the two different active materials in a single segmented bi-material electrode. This setup allows distinguishing the contribution of each material to the overall electrode performance. The characterization consisted of cyclic voltammetry and galvanostatic charge discharge cycling. The behavior of the bi-material electrode is essentially a linear combination of the behaviors of the two materials.