Pillaring-Effect Induced Ultrahigh-Rate Pseudocapacitive Energy Storage Based on Layered Double Hydroxide Nanoplate Arrays

Two-dimensional layered materials with large interlayer distance to guarantee facilitated electrolyte diffusion are regarded as good candidates for high-performance supercapacitors. In this work, NiAl-layered double hydroxide (LDH) nanoplate arrays with NO3–, pentanesulfonate (PS) and dodecanesulfonate (DS) ions in their interlayer were synthesized, and the effect of different pillaring anions on the electrochemical properties of LDH electrodes was investigated. Combined studies of experiments and theoretical calculations show that the pillaring-effect of long-chain molecules drastically reduces the ion transport resistance between the electrode and electrolyte. An enhanced specific capacitance (1125 F g–1 at 1 A g–1) and a ultrahigh-rate capability (72.8% retention at 200 A g–1) were achieved for the NiAl(DS)-LDH electrode. Such an electrode was further assembled into an all-solid-state supercapacitor, which exhibits a significantly improved energy and power densities as well as long-term stability. This...