Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composit...Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3(LAGP,NASICON-type structure) exhibits a high ionic conductivity(σi=0.17 mS cm-1) at 30℃,a transference number of 0.30,and is stable up to 5.0 V.The composite electrolyte is a flexible and self-standing membrane.Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g-1,high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30℃ and 0.1 C rate.These electrochemical properties are better than other PCL-based allsolid-lithium batteries,and validate the concept of "polymer-in-ceramic" by avoiding the drawback of lower conductivity in prior "polymer-in-ceramic" electrolyte at high concentration of the ceramic.展开更多
The in vitro and in vivo degradation behaviour of poly (ε-caprolactone) (PCL) has been examined in terms of degree of degradation and morphological change during an inclibation period of up to 300 d. Gel permeation c...The in vitro and in vivo degradation behaviour of poly (ε-caprolactone) (PCL) has been examined in terms of degree of degradation and morphological change during an inclibation period of up to 300 d. Gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) were employed to character ize their degradation profiles. The observation of the changes in intrinsic viscosity and average molecular weight as well as the crystallinity of PCL leads to the findings that 2 degradation mechanisms of PCL exist. The subcutaneous implant test shows that the rate of degradation in the rabbit body is much higher than in vitro. This illustrated that in vivo, the mechanism of bioerosion is more important than hydrolytic cleavage of ester linkage, especially in the second stage of degradation. Regardless of the initial Mn of specimens, a lin ear relationship between Mn and degradation time has been observed until the Mn decreased to be about 5 ooo D. Above this figure, the main degradation mechanism was hydrolytic cleavage of ester group accompa nied by enzymatic surface erosion, below this point, the bioerosion with weight loss plays a more significant role than hydrolytic reaction in their degradation. Comparison between the morphology of PCL materials af ter and before erosion was made by means of scanning electron microscopy (SEM).展开更多
基金supported by the National Key R&D Program of China (2016YFB0100500)Special fund of key technology research and development projects (20180201097GX) (20180201099GX) (20180201096GX) (20190302130GX)+1 种基金Jilin province science and technology department. The R&D Program of power batteries with low temperature and high energy, Science and Technology Bureau of Changchun (19SS013)Key Subject Construction of Physical Chemistry of Northeast Normal University。
文摘Inspired by the concept of "polymer-in-ceramic",a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3(LAGP,NASICON-type structure) exhibits a high ionic conductivity(σi=0.17 mS cm-1) at 30℃,a transference number of 0.30,and is stable up to 5.0 V.The composite electrolyte is a flexible and self-standing membrane.Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g-1,high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30℃ and 0.1 C rate.These electrochemical properties are better than other PCL-based allsolid-lithium batteries,and validate the concept of "polymer-in-ceramic" by avoiding the drawback of lower conductivity in prior "polymer-in-ceramic" electrolyte at high concentration of the ceramic.
文摘The in vitro and in vivo degradation behaviour of poly (ε-caprolactone) (PCL) has been examined in terms of degree of degradation and morphological change during an inclibation period of up to 300 d. Gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) were employed to character ize their degradation profiles. The observation of the changes in intrinsic viscosity and average molecular weight as well as the crystallinity of PCL leads to the findings that 2 degradation mechanisms of PCL exist. The subcutaneous implant test shows that the rate of degradation in the rabbit body is much higher than in vitro. This illustrated that in vivo, the mechanism of bioerosion is more important than hydrolytic cleavage of ester linkage, especially in the second stage of degradation. Regardless of the initial Mn of specimens, a lin ear relationship between Mn and degradation time has been observed until the Mn decreased to be about 5 ooo D. Above this figure, the main degradation mechanism was hydrolytic cleavage of ester group accompa nied by enzymatic surface erosion, below this point, the bioerosion with weight loss plays a more significant role than hydrolytic reaction in their degradation. Comparison between the morphology of PCL materials af ter and before erosion was made by means of scanning electron microscopy (SEM).
