High energy lithium ion capacitors using hybrid cathodes comprising electrical double layer and intercalation host multi-layers

Journal article

The ability to recharge and to deliver high capacity quickly is required for the next generation of lithium ion storage technologies, especially for pure electric vehicles. A new type of hybrid positive electrode for lithium ion capacitors is investigated that comprises discrete layers of high power capacitive activated carbon and high capacity insertion-type LiFePO4, with the aim of boosting energy density towards that of a lithium ion battery while preserving capacitor-like power capability over thousands of charge/discharge cycles. The electrochemical performance of these hybrid electrodes was investigated both as a function of the LiFePO4 weight fraction (its thickness in the multi-layered electrode arrangement) and its location within the multi-layer. The best performing hybrid positive electrode architecture delivered an attractive balance of an energy density of ~ 90 Wh/kg and a power density of ~ 15 kW/kg in a full lithium ion capacitor configuration, which outperformed other combinations of the same materials. The ability to produce a double-sided configuration of the hybrid layered electrode over 20 × 20 cm2 was demonstrated, confirming the potential scalability of layer-by-layer manufacture.

Authors: Lee, SH; Huang, C; Grant, PS

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Energy Storage Materials
• Volume: 33
• Pages: 408-415
• Publication date: 2020-09-01
• Acceptance date: 2020-08-24
• DOI: 10.1016/j.ensm.2020.08.022
• EISSN: 2405-8297
• Language: English
• Keywords: lithium ion capacitor; activated carbon; hybrid electrode; FFR; layer-by-layer spray painting; LiFePO4