基于阳离子空位储存机理的多价离子电池的构筑及性能研究

Rechargeable batteries are on the way to large-scale storage applications spanning electrification of transport to grid storage for renewable energies. Up to now, Li-ion batteries represent the state-of-the-art technology meeting best the increased demand in energy storage. However, the growing demand of Li raises fear on Li shortage. In addition, the uneven global distribution of Li could cause geopolitical concerns. In this scope, the proposed proposal aims to create impact by developing innovative batteries’ technologies beyond Li-chemistry (i.e., Mg- and Al-chemistry) capable of promoting Chinese Energy Initiative with respect to the sustainability and the competitiveness of Chinese policy on the renewable energy. From the sustainability point of view, Mg and Al are promising alternatives to Li due to their abundance and low cost. However, current intercalation compounds commonly used in Li-chemistry are not suitable for the purpose. The main issue is still the identification of new multivalent ions (Mg and Al) intercalation compounds. In this context, the present project will investigate a fundamental and applied research for the development of transition metal oxides incorporated with defect chemistry, and to apply them as electrodes for multivalent ions (Mg and Al) batteries. The concept that will be put in light is devoted to tailor the atomic structure of transition metal oxides featuring cationic vacancies by the substitution of oxides using hydroxides and/or fluorides based on the soft chemistry, and understand the multivalent-ion intercalation processes.

锂离子电池是目前应用最广泛的储能技术，满足能源储存需求的增长。然而，锂离子电池需求的增加导致了对锂资源短缺的担忧，全球锂资源分布不均也会引起地域政治方面的担忧。大力推进后锂离子电池成为亟待解决的问题，是制约我国储能系统多样化布局的重要因素。低成本的多价镁离子和铝离子电池的发展具有很强的吸引力，由于其具有很高的资源储量和广泛的分布。但是，多价离子与氧化物晶格之间强烈的静电斥力阻碍了其嵌入和扩散过程，导致储存锂离子的可用氧化物表现出对多价离子储存的惰性。激发氧化物对镁离子和铝离子的储存性能是多价离子电池发展的挑战。本项目将探讨缺陷氧化物在多价离子电池中的应用，在制备过程中引入阳离子空位，从而制备出适用于多价离子电池的先进材料。从基础研究开始，通过掺杂、使用低温水热法制备和优化阳离子空位缺陷氧化物，以物理化学及电化学方法表征缺陷材料，建立材料的结构-性能关系，阐明多价离子嵌入机理。

全球锂离子电池需求的增加导致了对锂资源短缺的担忧，大力推进后锂离子电池成为亟待解决的问题。低成本多价离子电池的发展具有很强的吸引力，由于其具有很高的资源储量和广泛的分布。但是，多价离子与氧化物晶格之间强烈的静电斥力阻碍了其嵌入和扩散过程，导致多数氧化物表现出对多价离子储存的惰性。本项目基于改善多价离子在氧化物材料中的扩散动力学，在氧化物制备过程中引入了阳离子空位，激发了氧化物储存多价离子的潜能。此外，本项目研究了缺陷氧化物在多价离子电池中的应用，制备出适用于多价离子电池的先进材料。本项目聚焦于缺陷化学的基础研究，构筑了一系列具有阳离子空位的缺陷氧化物，如：Ti基、Mn基和Fe基缺陷氧化物，并以先进的物理化学方法表征了缺陷氧化物的晶体结构和电子结构，结合电化学性能揭示了缺陷材料的结构-性能关系，为改善多价离子电池的性能提供了理论基础和解决方案。