High-Performance Quasi-Solid-State Supercapacitor Based on CuO Nanoparticles with Commercial-Level Mass Loading on Ceramic Material La1-xSrxCoO3-δ as Cathode

To evaluate the performance of supercapacitor objectively and accurately, it is critical to develop an electrode with a thickness in the hundred-micrometer range and commercial-level mass loading of active material. In this work, for the first time, high mass loading CuO as active material (10 mg cm–2) is supported on La1-xSrxCoO3-δ (LSC, 0 ≤ x ≤ 0.8) substrate (thickness: ∼ 500 μm) and used as a cathode for asymmetric supercapacitor. The novel and binder-free CuO/LSC73 (i.e., x = 0.3) electrode shows high areal (Ca, 5.45 F cm–2) and specific (Cs, 545 F g–1) capacitances. The packaged quasi-solid-state asymmetric supercapacitor with PVA/KOH gel as an electrolyte and carbon cloth as an anode, delivers an ultrahigh volumetric energy density of 4.92 mWh cm–3 at 10 mA cm–2 in a wide potential window of 1.4 V, which is comparable to those of lithium batteries (∼0.3–10 mWh cm–3). In addition, power density of the assembled device can reach 727 mW cm–3 at 80 mA cm–2 with a high energy density of 3.03 mWh cm–3. T...