Zinc-ion hybrid supercapacitor-batteries with a leaf-like ZIF-L/MgNiO2 micro-sphere composite and a Zn2+/sulfonated poly(ether ether ketone) gel

A long-lasting, low cost, eco-friendly, air-processable ZIF-L/MgNiO 2 //Zn 2+ /SPEEK//ZnμPs-AC based zinc-ion hybrid supercapacitor battery (ZHSB) with an optimal balance between high power density (0.8–8 kW kg −1 ) and high energy density (157–89 W h kg −1 ), a capacity of 197 mA h g −1 (at 1 A g −1 ) and an ultra-long cycle life of ∼10 000 cycles is presented.