单相多元金属氧化物—掺杂碳基复合材料的多孔结构设计及其锂离子电容器性能研究

Lithium-ion capacitors, with high energy density and high power density, are expected to be the next generation of energy storage devices, which can overcome the low energy density of supercapacitors and low power density of lithium-ion batteries. The pseudocapacitive electrode material with high-performance is the hinge for lithium-ion capacitors. In this program, we will synthesize the high-performance composites combined with the doped carbon materials and single-phase multi-metal oxides (AxByOz: A, B=Fe, Co, Ni, Mn, Zn), by using green chemical techniques, in which the surface modification and the nano-interface engineering with hybrid synergistic effects are applied. The high electrochemical activities of multi-metal oxides, and the more active sites of doped carbon with well stability and conductivity, together with high synergistic effect of the hybrid nano-interface and the 3D porous structure of nanocomposites, are all beneficial for lithium-ion diffusion and electron transfer, which would lead to the well rate performance, high energy density, high power density and long cycle lifetime. The doped degree and mode of carbon materials, the crystal structure and morphology of metal oxides, as well as the fine structure and the lithium-ion capacitor performance of the 3D composites synthesized, will be systematically investigated. The structure-performance relationship will be explored. The interactions among components of the composites and the energy storage mechanism in lithium-ion capacitors will also be investigated. It is of significance that this program can provide valuable theoretical guidance and experiment technical guarantee for the development of novel lithium-ion capacitors.

高比能量、高比功率的锂离子电容器可以弥补超级电容器比能量低和锂离子电池比功率低的不足，有望成为新一代的储能装置，关键在于获得高性能的赝电容电极材料。项目采用绿色化学工艺，通过表面修饰和杂化协同纳米界面工程，制备高性能单相多元金属氧化物（AxByOz：A，B=Fe, Co, Ni, Mn, Zn）—掺杂碳基复合材料。充分利用多元金属氧化物的高电化学活性，掺杂碳的多活性位点、高导电性和稳定性，复合材料的杂化纳米界面的高协同性及3D多孔特性，提高电子传递和离子扩散速率，从而提升电极材料的倍率特性、比能量、比功率和循环寿命等综合性能。系统研究碳材料掺杂方式和程度、金属氧化物纳米晶的晶相及形貌、复合材料的3D多孔精细结构和锂离子电容器性能；揭示复合电极材料的构效关系；探讨复合材料组分之间的相互作用和储电机理。该项目研究为推动新型锂离子电容器的发展提供理论指导和实验技术保障，具有重要意义。

高比能量、高比功率的锂离子电容器可以弥补超级电容器比能量低和锂离子电池比功率低的不足，有望成为新一代的储能装置，关键在于获得高性能的赝电容电极材料。项目（No. 21576138）在基金委的资助下，圆满完成了原定的研究任务和目标。根据研究计划书，采用绿色化学工艺，通过表面修饰和杂化协同纳米界面工程，获得了高性能的单相多金属氧化物-碳基复合电极材料，研究了这些材料的储锂和电容性能，及其锂离子电容器性能。充分利用杂化纳米界面的高协同性及3D多孔结构，有效提高了电子传递和离子扩散速率，提升了电极材料和器件的倍率特性、比能量、比功率和长循环寿命等综合性能。系统研究了复合体系的晶相、形貌以及杂化界面的高协同性与电化学性能的关系；探讨了组分之间的相互作用和储电机理。合成的材料还在其他电化学体系有着良好的应用前景，拓展了两个新方向。该项目共获得高性能、多层次结构的多元金属氧化物/碳复合电极材料17种，发展了多层次复合材料的合成技术和工艺10个，共发表SCI期刊论文30篇，申请国家发明专利16项，其中获授权3项。培养了博士后2名，其中出站博士后1，在站1名。培养研究生28名，其中获得博士学位5名，在读博士研究生7名，获得硕士学位10名，在读硕士研究生6名。该项目研究为推动新型锂离子电容器的发展提供理论指导和实验技术保障,培养了一批高层次人才，具有重要的科学和社会意义。