Polyoxometalates(POMs)with multiple redox active sites have been reported as charge sponge for lithium-ion batteries(LIBs).Herein,we for the first time introduce a polyoxovanadate(POV)ionic crystals with macrocations,...Polyoxometalates(POMs)with multiple redox active sites have been reported as charge sponge for lithium-ion batteries(LIBs).Herein,we for the first time introduce a polyoxovanadate(POV)ionic crystals with macrocations,[Ni(Phen)_(3)][ClV_(14)O_(34)]Cl(NiV_(14),Phen=1,10-phenanthroline),as an anode material for LIBs.The existence of macrocation[Ni(Phen)_(3)]^(2+)stabilizes the open tunnels inside NiV_(14).The NiV_(14)electrode exhibits superior rate capabilities(1083 mAh·g^(-1)at 100 mA·g^(-1)and 384 mAh·g^(-1)at 2000 mA·g^(-1))due to the rapid capacitive dominated contribution and high Li^(+)ions diffusion coefficients(3.3×10^(-12) cm^(-2)·s^(-1)),and it delivers a remarkable cycling stability with a Coulombic efficiency of 99.7%after 1000 cycles at 2000 mA·g^(-1).Such performance can be attributed to the stable structure of NiV14 and the highly reversible valence changes of vanadium during the charge/discharge processes,which are revealed by a combination of in situ X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and X-ray absorption fine structure(XAFS)measurements.This work not only demonstrates that NiV_(14) with open tunnels stabilized by macrocation is a promising anode material for high performance LIBs,but also provides important references for the rational design of POMs electrode materials in advanced energy storage systems.展开更多
基金We acknowledge support from Hefei National Laboratory for Physical Sciences at the Microscale,Hefei Science Center of Chinese Academy of Sciences,Fujian Institute of Innovation of Chinese Academy of Sciences,the National Natural Science Foundation of China(Nos.21571167,51502282,and 22075266)the Fundamental Research Funds for the Central Universities(Nos.WK2060190053 and WK2060190100).
文摘Polyoxometalates(POMs)with multiple redox active sites have been reported as charge sponge for lithium-ion batteries(LIBs).Herein,we for the first time introduce a polyoxovanadate(POV)ionic crystals with macrocations,[Ni(Phen)_(3)][ClV_(14)O_(34)]Cl(NiV_(14),Phen=1,10-phenanthroline),as an anode material for LIBs.The existence of macrocation[Ni(Phen)_(3)]^(2+)stabilizes the open tunnels inside NiV_(14).The NiV_(14)electrode exhibits superior rate capabilities(1083 mAh·g^(-1)at 100 mA·g^(-1)and 384 mAh·g^(-1)at 2000 mA·g^(-1))due to the rapid capacitive dominated contribution and high Li^(+)ions diffusion coefficients(3.3×10^(-12) cm^(-2)·s^(-1)),and it delivers a remarkable cycling stability with a Coulombic efficiency of 99.7%after 1000 cycles at 2000 mA·g^(-1).Such performance can be attributed to the stable structure of NiV14 and the highly reversible valence changes of vanadium during the charge/discharge processes,which are revealed by a combination of in situ X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and X-ray absorption fine structure(XAFS)measurements.This work not only demonstrates that NiV_(14) with open tunnels stabilized by macrocation is a promising anode material for high performance LIBs,but also provides important references for the rational design of POMs electrode materials in advanced energy storage systems.
