For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, a...For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, andalusite, a-Al2O3 as the starting materials with non-contact graphite-buried sintering method. Phase composition and microstructure of the composites were investigated by XRD and SEM, and the effect of MnOz on the properties of SiC composites was studied. Results indicated that samples SM1 with 0.2 wt% MnO2 addition achieved the optimum properties： bending strength of 70.96 MPa, heat capacity of 1.02 J.（g.K）-1, thermal conductivity of 9.05 W-（m.K）-1. Proper addition of MnO2 was found to weaken the volume effect of the composites and improve the thermal shock resistance with an increased rate of 27.84% for bending strength after 30 cycles of thermal shock （air cooling from 1 100 ℃ to RT）. Key words： SiC-mullite composite ceramics; MnO2; solar sensible thermal storage; non-contact graphite-buried sintering; thermal shock resistance展开更多
Aqueous zinc-ion batteries,especially Zn-Mn02 battery,have attracted intensive attention owing to their unique features of high capacity,environmental friendliness,and safety.However,the problem of Mn dissolution hind...Aqueous zinc-ion batteries,especially Zn-Mn02 battery,have attracted intensive attention owing to their unique features of high capacity,environmental friendliness,and safety.However,the problem of Mn dissolution hinders the development of zinc-ion batteries with long-term usage and high-rate performance.In this work,a novel preparation method for the polyaniline(PANI)-coated composite aerogel of Mn02 and rGO(MnO2/rGO/PANI)electrode is reported.The obtained composite possesses high electrical conductivity,and also effectively suppresses the dissolution of Mn.The fabricated Mn02/rGO/PANI//Zn battery exhibits a high capacity of 241.1 mAh·g^-1 at 0.1 A·g^-1,and an excellent capacity retention of 82.7%after 600 charge/discharge cycles.In addition,the rapid diffusion coefficient of the Mn02/rGO/PANI electrode was further examined by galvanostatic intermittent titration technique.This work provides new insights into the development of high-performance Zn-Mn02 battery with a better understanding of its diffusion kinetics.展开更多
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2010CB227105)
文摘For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, andalusite, a-Al2O3 as the starting materials with non-contact graphite-buried sintering method. Phase composition and microstructure of the composites were investigated by XRD and SEM, and the effect of MnOz on the properties of SiC composites was studied. Results indicated that samples SM1 with 0.2 wt% MnO2 addition achieved the optimum properties： bending strength of 70.96 MPa, heat capacity of 1.02 J.（g.K）-1, thermal conductivity of 9.05 W-（m.K）-1. Proper addition of MnO2 was found to weaken the volume effect of the composites and improve the thermal shock resistance with an increased rate of 27.84% for bending strength after 30 cycles of thermal shock （air cooling from 1 100 ℃ to RT）. Key words： SiC-mullite composite ceramics; MnO2; solar sensible thermal storage; non-contact graphite-buried sintering; thermal shock resistance
基金supported by the National Natural Science Foundation of China(Nos.51602284 and 51702286)Natural Science Foundation of Zhejiang Province,China(Nos.LQ17B030002 and LR19E020003)General Scientific Research Project of the Department of Education of Zhejiang Province,China(No.Y201839638).
文摘Aqueous zinc-ion batteries,especially Zn-Mn02 battery,have attracted intensive attention owing to their unique features of high capacity,environmental friendliness,and safety.However,the problem of Mn dissolution hinders the development of zinc-ion batteries with long-term usage and high-rate performance.In this work,a novel preparation method for the polyaniline(PANI)-coated composite aerogel of Mn02 and rGO(MnO2/rGO/PANI)electrode is reported.The obtained composite possesses high electrical conductivity,and also effectively suppresses the dissolution of Mn.The fabricated Mn02/rGO/PANI//Zn battery exhibits a high capacity of 241.1 mAh·g^-1 at 0.1 A·g^-1,and an excellent capacity retention of 82.7%after 600 charge/discharge cycles.In addition,the rapid diffusion coefficient of the Mn02/rGO/PANI electrode was further examined by galvanostatic intermittent titration technique.This work provides new insights into the development of high-performance Zn-Mn02 battery with a better understanding of its diffusion kinetics.
