Substantially boosted energy density of NiCoMn layered double hydroxides with nanocrystalline-amorphous domains

To promote the energy density ( E ) of the hybrid asymmetric supercapacitance (ASC) device, both anode and cathode materials are crucial. The multi-component layered double hydroxides (LDH) as anode materials boost a surprisingly supercapacitance, while the functions of dual-phase nanodomains induced by multi-constituents on the electrochemical reactions are still puzzled and need to be explored. In this work, Ni 1 Co 1 Mn x (Ni/Co/Mn = 1/1/x) LDH microspheres are developed, characterizing by quantum-sized nanocrystals embedded in amorphous matrix modulated via Mn doping. The specific capacities ( C ) of Ni 1 Co 1 Mn 1.5 reach up to 5750 at 1 A g −1 and 5300 F g −1 at 10 A g −1 , exceeding four times of 1367 (1 A g −1 ) and 1133 F g −1 (10 A g −1 ) of the Ni 1 Co 1 Mn 0 counterpart. To break through the upper limit of the traditional active cardon cathode, bamboo-derived porous carbon (BPC) powders are produced from green raw resource by two stages calcination to increase the C . The assembled ASC cell with Ni 1 Co 1 Mn 1.5 as an anode and BPC as a cathode possesses a large E of 97.8 Wh kg −1 at a power density ( P ) of 749.2 W kg −1 . An exceptional sustainability of Ni 1 Co 1 Mn 1.5 //BPC device is attained with 91.4 % retention after 8000 cycles at a large charging current of 10 A g −1 . The insights of Mn-regulated transition of nanocrystal-amorphous microstructure and the enhanced energy storage performance are explored.