Smart Multi‐Layer Architecture Electrodes for High Energy Density Lithium‐Ion Capacitors

Abstract

AbstractMulti‐layer architectures for use in both negative and positive electrodes are developed through a layer‐by‐layer spray printing approach using complementary material combinations, with the ultimate goal to realize an ideal concept of hybrid lithium‐ion capacitors more fully – delivering attractive energy densities of insertion‐type negative electrodes while preserving outstanding power performances of activated carbon positive electrodes. To sustain advantageous capacities of intercalation anodes even at ultra‐fast charging rates, a thin, discrete layer of high capacity Si was interleaved between high power Li4Ti5O12 electrodes. In a cathode electrode, a sequential layer of insertion‐type LiFePO4 was assembled with a conventional activated carbon layer into a single layer structure, aiming at boosting overall deliverable capacities. The lithium‐ion capacitor comprising the smart multi‐layer architectures of negative and positive electrodes then provided a remarkable energy density of ∼110 Wh/kg with an outstanding power performance of 15 kW/kg.