Electrolyte decomposition reactions on Li-ion battery electrodes contribute to the formation of solid electrolyte interphase (SEI) layers. These SEI layers are one of the known causes for the loss in battery voltage and capacity over repeated charge/discharge cycles. In this work, density functional theory (DFT)-based ab-initio calculations are applied to study the initial steps of the decomposition of the organic electrolyte component ethylene carbonate (EC) on the (10-14) surface of a layered Li(Nix,Mny,Co1-x-y)O2 (NMC) cathode crystal, which is commonly used in commercial Li-ion batteries. The effects on the EC reaction pathway due to dissolved Li+ ions in the electrolyte solution and different NMC cathode surface terminations containing absorbed hydroxyl -OH or fluorine -F species are explicitly considered. We predict a very fast chemical reaction consisting of an EC ring-opening process on the bare cathode surface, the rate of which is independent of the battery operation voltage. This EC ring-opening reaction is unavoidable once the cathode material contacts with the electrolyte because this process is purely chemical rather than electrochemical in nature. The -OH and -F adsorbed species display a passivation effect on the surface against the reaction with EC, but the extent is limited except for the case of -OH bonded to a surface transition metal atom. Our work implies that the possible rate-limiting steps of the electrolyte molecule decomposition are the reactions on the decomposed organic products on the cathode surface rather than on the bare cathode surface.
Flexible, solid electrolyte-based lithium battery composed of LiFePO4 cathode and Li4Ti5O10 anode for applications in smart textiles
在这里，我们报告制造的灵活和可拉伸的电池组成的应变自由LiFePO 4阴极，Li 4 Ti 5 O 10阳极和固体聚环氧乙烷（PEO）电解质作为隔膜层。该电池是从智能纺织品应用的角度开发的。该电池以固体热塑性电解质为关键使能元件，可挤压或拉伸成纤维或细条，直接与智能纺织品制造中使用的编织工艺兼容。本文首先详细介绍了材料的选择，电极和隔膜层的制造和表征。然后组装电池并对其进行表征，最后，将由几个长条制成的大型电池样品编织成织物，用导电线连接，并进行表征。在本文中，我们详细研究了电池设计的两个实际方面：第一是以导电碳和聚合物粘合剂材料的优化比例制备阴极/阳极材料的复合材料，第二是电池性能，包括循环，可逆性和阴极/阳极材料的相容性。最后，当铸造电极和隔膜层时，我们主要关注使用水溶液代替有机溶剂，以使制造过程环境友好。
Extracting a nitrile-centered, ether-assisted motif hierarchy for lithium-battery electrolyte design from billion-scale molecular space
University of Science and Technology of China（中国科学技术大学）；Suzhou Institute for Advanced Research, University of Science and Technology of China（中国科学技术大学苏州高等研究院）；Suzhou Big Data & AI Research and Engineering Center（苏州大数据与人工智能研究与工程中心）；Contemporary Amperex Technology Co. Limited（宁德时代新能源科技股份有限公司）；AI for Science Institute（人工智能科学研究所）
