基于自腐蚀原理的多孔结构过渡金属(Fe, Co)草酸盐/氧化物一维微纳米阵列电极的可控制备及其电化学储锂性能

Transition metal (Fe, Co) oxalates/oxides are considered as promising anode materials for lithium-ion batteries because of their distinctive properties, such as high lithium storage capacity, low cost and environmental friendship. However, the electrochemical cycle stability of the investigated transition metal oxalates/oxides is relatively poor, and their reversible capacities need to be further improved. In this project, one-dimensional (1D) transition metal (Fe, Co) oxalate crystals micro-nanoarray films are fabricated by the method based on self-corrosion principle, and the subsequent heat treatments lead to the formation of anhydrous oxalates/oxides 1D micro-nanoarray films, and then the lithium storage properties of these anhydrous 1D micro-nanoarray films are probed in detail. The electrode processes and formation mechanisms of the transition metal oxalate crystals 1D micro-nanoarray films fabricated by the method based on self-corrosion principle are explored, and the effects of metal precursor, oxalic acid solution, temperature and immersion time on the micro-nanoarray films are investigated. The key preparative factors are identified, and finally the controllable fabrication of the transition metal oxalate crystals 1D micro-nanoarray films is realized. We try to clarify the effects of heat treatment parameters on the compositions and microstructures of the anhydrous oxalates/oxides 1D micro-nanoarray films. The intrinsic relationship between the lithium storage properties and microstructures of the anhydrous oxalates/oxides 1D micro-nanoarray films needs to be elucidated. It is expected that the effective approaches for improving the lithium storage performance are identified, and the anhydrous oxalates/oxides 1D micro-nanoarray films with superior lithium storage performance can be obtained.

过渡金属(Fe, Co)草酸盐/氧化物具有储锂容量大、成本低及环境友好等优异特性, 被视为极具潜力的锂离子电池阳极材料. 但其存在着电化学稳定性较差、实际可逆容量有待于提高等问题. 本项目基于自腐蚀反应原理制备过渡金属(Fe, Co)草酸盐晶体一维微纳米阵列膜, 进一步通过适当的热处理获得无水草酸盐/氧化物一维微纳米阵列膜, 并探究其电化学储锂性能. 系统研究基于自腐蚀反应原理制备过渡金属草酸盐晶体一维微纳米阵列膜的电极过程与成膜机制, 探明金属层的组成与结构、草酸浸蚀液的组成、浸蚀温度及时间等参数对一维微纳米阵列膜结构的影响规律, 明晰膜制备的关键控制因素, 实现过渡金属草酸盐晶体一维微纳米阵列膜的可控制备. 查明热处理条件对过渡金属无水草酸盐/氧化物一维微纳米阵列膜组成及微观结构的影响规律, 揭示这些微纳米阵列膜的储锂性能与微观结构的内在关联, 明晰提高其电化学储锂性能的有效途径.

过渡金属(Fe, Co)草酸盐/氧化物具有储锂容量大、成本低及环境友好等优异特性，被视为极具潜力的锂离子电池阳极材料。本项目系统研究了基于自腐蚀反应原理制备过渡金属草酸盐一维微纳米阵列膜的成膜机制，明晰了膜制备的关键控制因素。查明了热处理条件对过渡金属无水草酸盐/氧化物一维微纳米阵列膜组成及微观结构的影响规律，揭示了这些微纳米阵列膜的储锂性能与微观结构的内在关联，明晰了提高其电化学储锂性能的有效途径。本项目主要获得了如下具有创新性的研究成果。.（1）基于金属铁在草酸溶液中的自腐蚀反应，我们制备了草酸亚铁纳米管阵列电极，提出了其形成机制。在氢气气氛下，对草酸亚铁纳米管阵列膜进行热处理，获得了氧化铁/碳复合纳米管阵列膜。在4A/g的电流密度下恒流充放电500次后，电极的可逆储锂容量为880 mAh/g，表明其具有优异的电化学循环性能。这主要归于其纳米管阵列结构及碳的原位形成。 .（2）基于电沉积钴层在含有尿素溶液中的自腐蚀反应，制备了顶部交叉的四氧化三钴纳米线束阵列膜，提出了四氧化三钴纳米线束阵列膜的形成机制。所制备的四氧化三钴纳米线束阵列膜电极显示了优异的储锂性能。.（3）通过低温溶剂热/水热法制备了CoO微米花和CoO微米球膜电极。两种膜电极均显示了突出的电化学储锂性能。微米花和微米球的分级多孔结构、自支持的膜结构以及高的比表面积是两种膜电极显示增强的电化学储锂性能的主要原因。.（4）采用一种简单的自腐蚀方法，制备了草酸铁微管阵列膜，提出了一种管状材料形成的新机制。对草酸铁微管阵列膜进行热处理，得到了氧化镍微管阵列膜，以其为基体，通过阳极电沉积法制备了MnO2/NiO复合微管阵列膜。与氧化镍微管阵列膜电极相比，MnO2/NiO复合微管阵列膜电极显示了显著增强的电化学储锂性能。