Layered double hydroxide (LDH) has shown great potential for energy storage due to their high theoretical specific capacitance, relatively low cost and eco-friendliness. LDH, however, always works in alkali aqueous electrolyte for supercapacitors, which brings serious environmental pollution. In this work, a reduced graphite oxide/Fe(CN)(6)(3-) - nickel cobalt aluminum LDH (RGO/Fe(CN)(6)(3-) - LDH) composite has been prepared via ion-exchange reaction using RGO/LDH as precursor. RGO/Fe(CN)(6)(3-) -LDH electrode provides a specific capacitance of 221 F g(-1) in a wide potential window of -1 similar to 0.8 V vs. SCE in Na2SO4 aqueous electrolyte, and which is much higher than that of LDH electrode (3.56 F g(-1)). Owing to the wide potential window of RGO/Fe(CN)(6)(3-) -LDH electrode, a symmetrical solid supercapacitor device (RGO/Fe(CN)(6)(3-) -LDH//RGO/Fe(CN)(6)(3-) -LDH) with a high voltage of 2.0 V can deliver a high specific energy of 25.2 Wh kg(-1) at a specific power of 250 W kg(-1), and a capacitance retention of 75% after galvanostatic charging/discharging at 5 A g(-1) for 5000 times. This work supplies enlightenment for boosting the capacitive performance of LDHs in neutral electrolyte. (C) 2020 Elsevier Inc. All rights reserved.