Composite LiFePO4/AC high rate performance electrodes for Li-ion capacitors

This manuscript reports the performance of composite electrodes based on the mixture of two, electrochemically active, materials: lithium iron phosphate (LiFePO4) and activated carbon (AC). The sodium salt of carboxymethylcellulose (CMC) was used as binder to cast the composite electrodes out of aqueous slurries. The investigated electrodes display high specific capacity and high cycling stability. Upon constant current tests with a charge rate of 50C and a discharge rate of 1D, the electrodes display a capacity of ca. 70 mAh g−1 while 60 mAh g−1 are delivered during pulse sequence tests at 100C. These results indicate such electrodes as promising candidates for the realization of lithium-ion capacitors.

Research highlights▶ LiFePO4 and activated carbon as active materials for Li-ion capacitor cathode. ▶ Composite electrodes based on aqueous processing containing CMC as binder. ▶ Increased electronic conductivity compared to carbon-black containing electrodes. ▶ About 70 mAh g−1 in charge-discharge tests at 50C/1D.