CAJ | 학술논문

碳气凝胶由于其对于可充电锂离子电池的高能嵌锂特性,近年来受关注程度逐渐增加.碳气凝胶以间苯二酚-甲醛在碳酸钠催化下,通过溶胶-凝胶工艺、常压干燥技术、碳化、活化后制得.经CO2气体活化后的碳气凝胶结合了无定型和纳米多孔结构的优点,在材料原有基础上丰富了多孔结构,增加了嵌锂点位.其中,微孔提供了高比表面积和孔体积以容纳锂及其化合物;介孔则提供了锂离子大量传输的通道,从而使得电极具有更高的离子电导率.这些微结构的优化使材料获得了更高的嵌锂比容量.此外,活化碳气凝胶显示了2032 m2·g-1的比表面积. X射线衍射(XRD)和扫描电子显微镜(SEM)的测试结果分别表明了其无定型特质以及纳米颗粒的网络状骨架.该材料在首次和第50次恒流充放电(50 mA·g-1)循环的嵌锂容量分别为3870和352 mAh·g-1,对应的可逆容量分别为658和333 mAh·g-1.表明了CO2活化对于改善碳气凝胶嵌锂性能的可行性,且对于其它多孔电极材料的制备及特性优化提供了一种途径.
탄기응효유우기대우가충전리리자전지적고능감리특성,근년래수관주정도축점증가.탄기응효이간분이분-갑철재탄산납최화하,통과용효-응효공예、상압간조기술、탄화、활화후제득.경CO2기체활화후적탄기응효결합료무정형화납미다공결구적우점,재재료원유기출상봉부료다공결구,증가료감리점위.기중,미공제공료고비표면적화공체적이용납리급기화합물;개공칙제공료리리자대량전수적통도,종이사득전겁구유경고적리자전도솔.저사미결구적우화사재료획득료경고적감리비용량.차외,활화탄기응효현시료2032 m2·g-1적비표면적. X사선연사(XRD)화소묘전자현미경(SEM)적측시결과분별표명료기무정형특질이급납미과립적망락상골가.해재료재수차화제50차항류충방전(50 mA·g-1)순배적감리용량분별위3870화352 mAh·g-1,대응적가역용량분별위658화333 mAh·g-1.표명료CO2활화대우개선탄기응효감리성능적가행성,차대우기타다공전겁재료적제비급특성우화제공료일충도경.
@@@@Abstrct: Carbon aerogels have received much recent attention as high-capacity insertion anodes for rechargeable lithium ion batteries. Carbon aerogels were synthesized from resorcinol-formaldehyde with a sodium carbonate catalyst via a sol-gel process, ambient drying, carbonization, and activation. Gaseous CO2-activated carbon aerogels combined the advantages of amorphous and nanoporous structures, with richer porous structures and more lithium insertion points than conventional carbon aerogels. Microporosity analysis indicated a high surface area, and the pore volume effectively retained lithium and its compounds. The mesoporosity al owed the mass transport of Li+and conferred high ionic conductivity to the electrode. These improvements led to a higher lithium insertion capacity, and the activated carbon aerogel exhibited a specific surface area of 2032 m2·g-1. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed an amorphous structure and nanoparticle network skeleton, respectively. Lithium insertion capacities of 3870 and 352 mAh·g-1 were exhibited in the 1st and 50th galvanostatic discharge-charge (50 mA·g-1) cycles, respectively. This corresponded to irreversible capacities of 658 and 333 mAh·g-1, respectively. This work demonstrates the feasibility of CO2 activation for improving lithium insertion performance in carbon aerogels, and provides preparation and optimization procedures for other porous electrode materials.