Solid-state energy storage devices exhibit superior safety and energy density. However, their practical applications are still limited by the lower conductivity and ion transfer rate. The performances of sodium ion capacitors (SICs) are determined by the combination of device configuration, electrodes, and electrolyte. Therefore, the configuration optimization of solid-state SICs (SS-SICs) is critically important. Here, the fabrication of a safer high-energy-density SS-SIC is demonstrated by using flake-shaped molybdenum disulfide/carbon nanotube nanohybrids and sodium-ion ionogel electrolytes. The microstructures of nanohybrids could support shortened migration paths for sodium ions and can buffer the volume change of electrochemical reactions. Moreover, the optimized sodium-ion ionogel electrolyte was found to exhibit improved flame-retardant ability, accelerated ionic conductivity, and excellent sodium migration rate. Electrochemical analysis and molecular simulation methods of energy storage behaviors were used to uncover the origin of improved performances at higher temperatures. The optimized SS-SIC could deliver a high energy density up to 115.7 W h kg(-1) at 70 degrees C and excellent durability with 81% retention after 8000 cycles. Therefore, a new energy supply device is provided for equipment operating at higher temperatures. (C) 2020 Elsevier Ltd. All rights reserved.