生物碳框架C/Zn_(1-x)Co_(x)O锂电负极材料

C/Zn_(1-x)Co_(x)O Composite Materials with Biochar Framework as Anode of Lithium-Ion Batteries

采用水热-煅烧法,以柚子皮内瓤、硝酸盐、尿素为起始物,制备出以多孔碳为框架、少量Co掺杂的C/Zn_(1-x)Co_(x)O复合材料,用作锂离子电池负极.XRD测试显示,Co掺杂未改变ZnO的晶型结构;SEM测试显示,样品为多孔薄片状碳框架包裹的Co掺杂ZnO纳米粒子.充放电、阻抗测试结果显示,相对于未掺杂Co的C/ZnO材料,少量Co的掺杂可以提高材料的导电性,从而提高材料的充放电容量和首圈库伦效率.0.1 A·g^(-1)时,C/Zn_(0.90)_(0.10)O样品容量可达400 mAh·g^(-1)以上并且可稳定运行100次以上.这一研究展示了资源化利用生物废弃物,并使之成为便宜、可持续应用的新能源材料的可能性.

In this study,C/Zn_(1-x)Co_(x)O composite materials,with a porous biochar framework and a small quantity of doped Co in nanosized ZnO particles,were prepared from pomelo peels,nitrate and urea through the hydrothermal and calcination method.These materials could be applied as anode of lithium-ion batteries.The X-ray powder diffraction(XRD)patterns showed that Co doping did not change the crystal type or lattice spacing of wurtzite ZnO.The scanning electron microscope(SEM)images showed that these materials were Co-doped ZnO nanoparticles enclosed with lamellar porous biochar frameworks.The charge-discharge and impedance measurement results indicated that the doping of a small quantity of Co could improve the conductivity of the materials and in turn improve the specific capacitance and the 1st-scan coulombic efficiency,as compared to the properties of C/ZnO composite without Co doping.At 0.1 A·g^(-1),the capacitance of C/Zn_(0.90)Co_(0.10)O could exceed 400 mAh·g^(-1) and could be stably cycled more than 100 times.Therefore,this study demonstrates the possibility of recycling the biowaste and converting it into a cheap and sustainable new energy material.