700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising similar to 240-mu m-thick activated carbon cathodes, and similar to 60-mu m-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g(-1)), good rate capabilities (148 mAhh g(-1) at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg(-1), a maximum power density of 2466 W kg(-1), and similar to 92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses. (C) 2017 Elsevier B.V. All rights reserved.