Effect of Pore Structures on the Electrochemical Performance of Porous Silicon Synthesized from Magnesiothermic Reduction of Biosilica  

作　　者：刘树和 LIU Bin YAO Yaochun DONG Peng ZHAO Shuchun 

机构地区：[1]National Engineering Research Center of Waste Recovery, Kunming University of Science and Technology, Kunming 650093, China,' [2]School of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China [3]Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2016年第5期965-971,共7页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(No.51264016);the Analysis and Testing Foundation of Kunming University o fScience and Technology,China(No.20140967)

摘　　要：Two kinds of porous silicon（PS） were synthesized by magnesiothermic reduction of rice husk silica（RHS） derived from the oxidization of rice husks（RHs）. One was obtained from oxidization/reduction at 500 ℃ of the unleached RHs, the other was synthesized from oxidization/reduction at 650 ℃ of the acidleached RHs. The structural difference of the above PS was compared： the former had a high pore volume（PV, 0.31 cm3/g） and a large specific surface area（SSA, 45.2 m^2/g）, 138 % and 17 % higher than the latter, respectively. As anode materials for lithium ion batteries, the former had reversible capacity of 1 400.7 m Ah/g, 987 m Ah/g lower than the latter; however, after 50 cycles, the former had 64.5 % capacity retention（907 m Ah/g）, which was 41.2 % higher than the latter（555.7 m Ah/g）. These results showed that the electrochemical performance of PS was significantly affected by its pore structures, and low reduction temperature played the key role in increasing its porosity, and therefore improving its cycling performance.Two kinds of porous silicon（PS） were synthesized by magnesiothermic reduction of rice husk silica（RHS） derived from the oxidization of rice husks（RHs）. One was obtained from oxidization/reduction at 500 ℃ of the unleached RHs, the other was synthesized from oxidization/reduction at 650 ℃ of the acidleached RHs. The structural difference of the above PS was compared： the former had a high pore volume（PV, 0.31 cm3/g） and a large specific surface area（SSA, 45.2 m^2/g）, 138 % and 17 % higher than the latter, respectively. As anode materials for lithium ion batteries, the former had reversible capacity of 1 400.7 m Ah/g, 987 m Ah/g lower than the latter; however, after 50 cycles, the former had 64.5 % capacity retention（907 m Ah/g）, which was 41.2 % higher than the latter（555.7 m Ah/g）. These results showed that the electrochemical performance of PS was significantly affected by its pore structures, and low reduction temperature played the key role in increasing its porosity, and therefore improving its cycling performance.

关 键 词：rice husks porous silicon lithium-ion batteries magnesiothermic reduction 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ127.2[化学工程—无机化工]