镶嵌于NH_(2)-MIL-125(Ti)衍生氮掺多孔碳中的花状超细纳米TiO_(2)作为高活性和稳定性的锂离子电池负极材料  

NH_(2)-MIL-125(Ti)Derived Flower-Like Fine TiO_(2)Nanoparticles Implanted in N-doped Porous Carbon as an Anode with High Activity and Long Cycle Life for Lithium-Ion Batteries

作　　者：杨越 朱加伟 王鹏彦 刘海咪 曾炜豪 陈磊[1] 陈志祥 木士春[1,2] Yue Yang;Jiawei Zhu;Pengyan Wang;Haimi Liu;Weihao Zeng;Lei Chen;Zhixiang Chen;Shichun Mu(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China;Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory,Xianhu Hydrogen Valley,Foshan 528200,Guangdong Province,China)

机构地区：[1]武汉理工大学,材料复合新技术国家重点实验室,武汉430070 [2]佛山仙湖实验室,先进能源科学与技术广东省实验室佛山分中心,广东佛山528200

出　　处：《物理化学学报》2022年第6期121-129,共9页Acta Physico-Chimica Sinica

基　　金：国家重点研发计划(2016YFA0202603);国家自然科学基金(22075223)资助项目。

摘　　要：由于具有高安全性和优异的循环稳定性,二氧化钛(TiO_(2))作为负极材料被广泛地应用于锂离子电池领域。但是较差的导电性和离子传输速率限制了TiO_(2)的进一步应用和发展。鉴于此,我们以花状NH_(2)-MIL-125(Ti)为前驱体和硬模板,成功合成出了具有花状结构的超细纳米TiO_(2)/多孔氮掺杂碳片(N-doped porous carbon)复合物(记为FL-TiO_(2)/NPC)。过程中所制备的纳米TiO_(2)-金属有机构架(Ti-MOF)展现出由二维褶皱多孔纳米片堆积、组装而成的花状结构。一方面,二维褶皱纳米片包含TiO_(2)纳米颗粒可以增大活性物质与电解液的接触面积;另一方面,氮掺杂多孔碳基体可以提高整体复合物的导电性和结构完整性。将所获得的FL-TiO_(2)/NPC作为负极组装成的锂半电池,在0.5 A·g^(−1)、300圈后仍有384.2 mAh·g^(−1)以及在1 A·g^(−1)、500圈仍有279.1 mAh·g^(−1)的比容量。进一步性能测试表明,在2 A·g^(−1)、2000圈长循环测试后,其仍能保持256.5 mAh·g^(−1)的比容量和接近100%的库伦效率。该优异的电化学活性和稳定性主要起源于材料独特的花状结构。我们的合成策略为今后制备高储锂性能的金属氧化物/多孔氮掺杂碳负极提供了一种新的思路。Owing to their advantages such as safe operation,high power density,long cycle life,and low self-discharge rate,lithium-ion batteries(LIBs)have attracted attention for applications ranging from portable electronics to electric vehicles(EVs)/hybrid EVs(HEVs).However,the striking exothermic reaction and growth of lithium dendrites during lithiation-delithiation cycles for commercial graphite anodes are hidden safety risks associated with LIBs.Titanium dioxide(TiO_(2))is considered as an important material for LIBs because of its high safety and excellent cycling stability.In addition,TiO_(2)anode used in lithium-ion storage system has a relatively high voltage(~1.5 V vs.Li/Li+),and thus,it meets the strict safety standards of commercial LIBs.However,the unsatisfactory conductivity and ion diffusion rate prevent the further application of TiO_(2) in LIBs.To date,the combination of graphene,carbon nanotubes(CNTs),carbon quantum dots(QDs)and porous carbon with TiO_(2) has attracted significant research attention.Nevertheless,it is still challenging to introduce a unique nanostructure design by organically compounding TiO_(2) with N-doped porous carbon matrix.Herein,N-doped porous carbon incorporating fine TiO_(2) nanoparticles(NPs)with a flower-like structure(denoted as FL-TiO_(2)/NPC)is successfully prepared using flower-like NH_(2)-MIL-125(Ti)as the hard template.The as-prepared Ti-based framework shows a flower-like structure,which is assembled with two-dimensional(2D)corrugated porous nanosheets.On the one hand,the corrugated carbon nanosheets incorporating fine TiO_(2) particles can offer a magnifying contact area between electrode matrix and electrolyte.On the other hand,the N-doped porous carbon plays a crucial role in improving the conductivity and structural integrity of the whole matrix.Therefore,the as-prepared FL-TiO_(2)/NPC can deliver an excellent reversible lithium storage capacity of 384.2 mAh·g^(−1)at the current density of 0.5 A·g^(−1)after 300 cycles and 279.1 mAh·g^(−1)at 1 A·g^(−1)afte

关 键 词：纳米TiO_(2) 氮掺杂多孔碳纳米片 花状结构 NH2-MIL-125(Ti) 负极 锂离子电池 

分 类 号：O643[理学—物理化学]