物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2014年
8期
1474-1480
,共7页
李庆洲%李玉惠%李亚娟%刘又年
李慶洲%李玉惠%李亞娟%劉又年
리경주%리옥혜%리아연%류우년
锂硫电池%石墨烯%水热法%硫代硫酸钠
鋰硫電池%石墨烯%水熱法%硫代硫痠鈉
리류전지%석묵희%수열법%류대류산납
Lithium-sulfur battery%Graphene%Hydrothermal method%Sodium thiosulfate
将硫代硫酸钠(Na2S2O3)与氧化石墨烯(GO)的混合溶液,在酸性条件下经过一步水热反应制备还原氧化石墨烯/硫(RGO/S)复合正极材料.实验探索了水热温度、反应时间、碳硫质量比例对材料的影响.通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和恒电流充放电对材料进行分析.结果表明在180°C下,碳硫质量比为3:7时,水热12 h得到的RGO/S复合材料具有优异的循环性能,首次放电比容量为931 mAh?g-1,50次循环之后其比容量还保持在828.16 mAh?g-1;RGO/S复合材料的充放电库仑效率在95%以上;同时RGO/S复合材料的倍率性能相比于单质硫有很大提高.一步水热法能够使硫分子均匀分布在石墨烯片层结构中,同时加强了石墨烯表面基团对硫分子的固定作用.
將硫代硫痠鈉(Na2S2O3)與氧化石墨烯(GO)的混閤溶液,在痠性條件下經過一步水熱反應製備還原氧化石墨烯/硫(RGO/S)複閤正極材料.實驗探索瞭水熱溫度、反應時間、碳硫質量比例對材料的影響.通過X射線衍射(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)和恆電流充放電對材料進行分析.結果錶明在180°C下,碳硫質量比為3:7時,水熱12 h得到的RGO/S複閤材料具有優異的循環性能,首次放電比容量為931 mAh?g-1,50次循環之後其比容量還保持在828.16 mAh?g-1;RGO/S複閤材料的充放電庫崙效率在95%以上;同時RGO/S複閤材料的倍率性能相比于單質硫有很大提高.一步水熱法能夠使硫分子均勻分佈在石墨烯片層結構中,同時加彊瞭石墨烯錶麵基糰對硫分子的固定作用.
장류대류산납(Na2S2O3)여양화석묵희(GO)적혼합용액,재산성조건하경과일보수열반응제비환원양화석묵희/류(RGO/S)복합정겁재료.실험탐색료수열온도、반응시간、탄류질량비례대재료적영향.통과X사선연사(XRD)、소묘전경(SEM)、투사전경(TEM)화항전류충방전대재료진행분석.결과표명재180°C하,탄류질량비위3:7시,수열12 h득도적RGO/S복합재료구유우이적순배성능,수차방전비용량위931 mAh?g-1,50차순배지후기비용량환보지재828.16 mAh?g-1;RGO/S복합재료적충방전고륜효솔재95%이상;동시RGO/S복합재료적배솔성능상비우단질류유흔대제고.일보수열법능구사류분자균균분포재석묵희편층결구중,동시가강료석묵희표면기단대류분자적고정작용.
Reduced graphene oxide/sulfur (RGO/S) composites were synthesized by a one-step hydrothermal method using a mixture of sodium thiosulfate (Na2S2O3) and graphene oxide (GO) solution reacting under acid conditions. We explored the influence of the hydrothermal temperature, reaction time, and sulfur content on the composites. Analysis by X-ray diffraction (XRD), scanning electron microscope (SEM), and the galvanostatic charge and discharge shows that the composites have excellent cycling performance when synthesis occurs at 180 °C for 12 h to provide a carbon:sulfur mass ratio of 3:7. The first discharge capacity is delivered at 931 mAh?g-1 and it remains at 828.16 mAh?g-1 after 50 cycles. The coulomb efficiency of the composites is above 95%. In addition, the rate capability of these composites is much better than that of sulfur. Sulfur molecules can be evenly distributed between the graphene layers and fixed to the functional groups on the surface of graphene by this one-step hydrothermal method.