Abstract
Metal coordination compounds(MCCs)are gaining popularity for potassium-ion batteries(PIBs)owing to their tuneable structure,multiple reaction sites,low cost and unique morphology.However,they are gen-erally subjected to intrinsic features of the sluggish ionic diffusion coefficient,low electronic conductivity and slow kinetics.Herein,a new MCC material of cobalt-1,3,5-tri-oxy-2,4,6-triamino-benzo(Co-TB)coordination compound was synthesized and homogenously grown on the surface of graphene nanosheets(GNS),forming a Co-TB@GNS composite with enhanced electronic conductivity and flexible capability.Benefiting from the overall enhanced conductivity,high surface area and abundant activated K-storage sites,Co-TB@GNS electrodes have exhibited superior cycling performance with high reversible capaci-ties(312mAh·g-1 after 100 cycles at 100mA·g-1,224 mAh·g-1 after 500 cycles at 1 A·g-1)and better rate performances compared with the pure Co-TB compound when served as PIB's anodes.Furthermore,multiple in-situ measurement techniques have jointly confirmed that the organic functional groups(C=O,C=N and C=C of benzene rings)and Co2+in Co-TB are the main reversible K-stor-age sites,including in-situ Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD),and partial capacity contribution is originated from GNS by the apparent K-storage behavior in the in-situ XRD pattern,proving the possibility of K-storage for metal-organic materials.
基金项目
National Natural Science Foundation of China(21975154)
National Natural Science Foundation of China(22179078)
Shanghai Municipal Education Commission(Innovation Program)(2019-01-07-00-09-E00021)
Innovative Research Team of Highlevel Local Universities in Shanghai()
NETL
NSTL
万方数据