A novel NiFe-LDH/RGO/CNFs composite was produced by using a facile one-step hydrothermal method as electrode for supercapacitor. Compared with NiFe-LDH/CNFs, NiFe-LDH/CNTs and NiFe-LDH/RGO, NiFe-LDH/RGO/CNFs demonstrated a high specific capacitance of 1330.2 F g⁻¹ at 1 A g⁻¹ and a super rate capability of 64.2% from 1 to 20 A g⁻¹, indicating great potential for supercapacitor application. Additionally, an asymmetric supercapacitor using NiFe-LDH/RGO/CNFs composite as positive electrode material and activated carbon as negative electrode material was assembled. The asymmetric supercapacitor can work in the voltage range of 0–1.57 V. It displayed high energy density of 33.7 W h kg⁻¹ at power density of 785.8 W kg⁻¹ and excellent cycling stability with 97.1% of the initial capacitance after 2500 cycles at 8 A g⁻¹. Two flexible AC//LDH-RGO-CNFs ASC devices connected in series were able to light up a red LED indicator after being fully charged. The results demonstrate that the AC//LDH-RGO-CNFs ASC has a promising potential in commercial application.

Ternary layered double hydroxide (LDH) materials have shown promising application in hybrid supercapacitors. However, the low electrical conductivity of LDHs is still a restriction to their performance. Herein, carbon nanotubes/cobalt–nickel–iron LDH (CNTs/CoNiFe-LDH) hybrid material was prepared by a one-step hydrothermal approach for the first time. The presence of CNTs improved the conductivity and surface area of the electrode, leading to an enhanced electrochemical performance. The CNTs/CoNiFe-LDH hybrid electrode exhibited high specific capacity 170.6 mAh g⁻¹ at a current density of 1 A g⁻¹, with a capacity retention of 75% at 10 A g⁻¹. CNTs/CoNiFe-LDH//AC asymmetric supercapacitor (ASC) was also assembled, which had high specific capacitance (96.1 F g⁻¹ at the current density of 1 A g⁻¹), good cycling stability (85.0% after 3000 cycles at 15 A g⁻¹) and high energy density (29.9 W h kg⁻¹ at the power density of 750.5 W kg⁻¹). Therefore, the CNTs/CoNiFe-LDH material could be used for hybrid supercapacitor electrodes.

We present here the synthesis of all polyester-based poly(butylene terephthalate)-block-poly(ethylene adipate) segmental multiblock copolymers (mBCPs), (PBT-b-PEA-b-PBT)_n, via a cascade polycondensation-coupling ring-opening polymerization (PROP) method using cyclic oligo(butylene terephthalate)s (COBTs) as monomers and polyethylene adipate (PEA) diol as the macroinitiator. The structure of copolyesters was characterized by ¹H quantitative NMR and ¹H–¹H gCOSY NMR spectroscopy, which reveals the randomly distributed copolyester segments in the main chains as the degree of randomness is equal to 1, arising from the transesterifications during PROP. Further investigations reveal that these segmental multiblock copolymers are elastomers with controlled properties, where the melting point, glass transition temperature (T_g), storage modulus, ratio of the loss modulus to the storage modulus (tan δ) and Young's modulus increase with the increment of the feeding content of COBTs, while the extensibility and biodegradable property decrease vice versa. The developed cascade polymerization method leads to the practical synthesis of environmentally-friendly biodegradable all polyester-based thermoplastic elastomers with tunable properties.