CAJ | 학술논문

通过溶胶-凝胶烧结法制备了 LiFePO 4/gra-phene 锂离子电池复合正极材料.采用 X 射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、循环伏安(CV)以及各种电化学检测技术对合成材料的结构、形貌进行了表征.LiFePO 4/graphene 复合材料的表面上和其中的 LiFePO 4微小颗粒之间都有石墨烯,说明石墨烯与 LiFePO 4已很好地融合在一起,形成了具有三维空间结构的立体导电网络,大大地提高了复合材料的电子导电性能及减少了电荷转移电阻,从而充分发挥了活性材料的全部潜力.电化学测量表明 LiFe-PO 4/graphene 的电化学性能比 LiFePO 4/C 更好. LiFePO 4/graphene 具有较高的比容量和优良的大倍率性能,在0．1和5 C 电流充放时,LiFePO 4/graphene的比容量分别为163．81和101．57 mAh/g,而 LiFe-PO 4/C 仅为146．05和54．67 mAh/g.LiFePO 4/gra-phene 也具有优良循环性能,0．5 C 循环100次,容量保持率为98．48％.
통과용효-응효소결법제비료 LiFePO 4/gra-phene 리리자전지복합정겁재료.채용 X 사선연사(XRD)、소묘전경(SEM)、투사전경(TEM)、순배복안(CV)이급각충전화학검측기술대합성재료적결구、형모진행료표정.LiFePO 4/graphene 복합재료적표면상화기중적 LiFePO 4미소과립지간도유석묵희,설명석묵희여 LiFePO 4이흔호지융합재일기,형성료구유삼유공간결구적입체도전망락,대대지제고료복합재료적전자도전성능급감소료전하전이전조,종이충분발휘료활성재료적전부잠력.전화학측량표명 LiFe-PO 4/graphene 적전화학성능비 LiFePO 4/C 경호. LiFePO 4/graphene 구유교고적비용량화우량적대배솔성능,재0．1화5 C 전류충방시,LiFePO 4/graphene적비용량분별위163．81화101．57 mAh/g,이 LiFe-PO 4/C 부위146．05화54．67 mAh/g.LiFePO 4/gra-phene 야구유우량순배성능,0．5 C 순배100차,용량보지솔위98．48％.
Three-dimensional LiFePO 4/graphene nanostructures for lithium-ion batteries were successfully pre-pared by a sol-gel sintering method.The synthesized material was characterized by means of X-ray diffraction (XRD),scanning electron microscope (SEM),transmission electron microscope (TEM)and a variety of elec-trochemical testing techniques.There were graphene sheets on the surface and among LiFePO 4 micro-nano-par-ticles of LiFePO 4/graphene composites,which indicates the graphene and LiFePO 4 of composites had be already nicely blended together.A three-dimensional conducting network of LiFePO 4/graphene composites was formed by graphene sheets,which greatly enhance the electronic conductivity and reduced charge transfer resistance, thereby realizing the full potential of the active materials.The electrochemical testing indicated that the electro-chemical properties of LiFePO 4/graphene was better than that of LiFePO 4/C.LiFePO 4/graphene composite ex-hibited high specific capacity and superior rate performance with the discharge capacities of 1 63.81 mAh/g at 0.1 C and 101.57 mAh/g at 5 C,whereas a discharge capacity of LiFePO 4/C was only 146.05 and 54.67 mAh/g respectively.LiFePO 4/graphene also showed an excellent cycling stability with only about 98.48% capacity re-tention at 0.5 C rate after 100 cycles.