Conditioning of all solid state Lithium Ion Batteries with LiMPO4 (M=Co, Ni) thin film cathodes

使用 LiMPO4 (M=Co, Ni) 薄膜阴极调节全固态锂离子电池

• 批准号: 268156926
• 负责人: Dr. Gennady Cherkashinin
• 金额: --
• 依托单位: Fachgebiet Oberflächenforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/268156926?language=en
• 关键词: Conditioning; solid; state; Lithium; Ion

The cathode material plays a key role in the determination of energy density, safety and life cycle of Lithium Ion Batteries (LIB). Its thermodynamic stability depends on the intrinsic voltage limit which is defined by the inherent oxidation limit of the anions within the relevant material. The extrinsic stability of the whole battery cell is additionally influenced by the redox potential of the electrolyte and by the chemical compatibility of the cathode/electrolyte interface. Power capability depends on the Li+ and/or electron transfer rates through the bulk cathode material and across the phase boundary cathode/electrolyte. Thus, to develop a stable high power and high density battery, the following key issues have to be solved: a) thermodynamic stability and chemical compatibility of the battery cell operated at a high voltage charged state; b) high migration rate of Li+ ions through the phases and across the phase boundaries; c) high electronic conductivity in the electrode and a blocking electrolyte interface. The specific role of these factors can hardly be clarified in classical battery structures due to the complexity of the set-up involving additives. The aim of our project is the preparation and investigation of novel high voltage solid state batteries. We focus on the olivine type structure material as LiMPO4 (M=Fe, Co, Ni) in which the voltage window is increased by substitution of Fe by Co (4.8 V) and Ni (> 5 V. The following scientific problems shall be addressed: a) Are LiCoPO4 and LiNiPO4 olivine-type cathode materials thermodynamically stable under delithiation and are they suitable for high voltage application up to a still unknown intrinsic voltage limit? b) Are LiCoPO4 and LiNiPO4 chemically compatible with typical electrolytes as fluoroethylene carbonate and is the olivine/electrolyte interface stable at voltage around 5 V? c) Are LiCoPO4 and LiNiPO4 chemically compatible with solid electrolytes (as e. g. LIPON)?The film cathode materials and their interfaces will be prepared under UHV condition and their electronic properties will be studied in situ mostly by using electron spectroscopy. With such a novel surface science approach applied at ion conductors we will address the intrinsic and extrinsic stability range of high voltage Olivines and investigate possible routes to avoid corrosive side reactions.

正极材料在决定锂离子电池（LIB）的能量密度、安全性和寿命周期方面起着关键作用。其热力学稳定性取决于固有电压极限，该极限由相关材料内阴离子的固有氧化极限限定。整个电池组电池的外在稳定性还受到电解质的氧化还原电位和阴极/电解质界面的化学相容性的影响。功率容量取决于通过本体阴极材料和跨越相边界阴极/电解质的Li+和/或电子转移速率。因此，为了开发稳定的高功率和高密度电池，必须解决以下关键问题：a）在高电压充电状态下操作的电池单元的热力学稳定性和化学相容性; B）Li+离子通过相和跨越相边界的高迁移速率; c）电极中的高电子电导率和阻塞电解质界面。由于涉及添加剂的设置的复杂性，这些因素的具体作用在经典电池结构中很难澄清。本项目的目标是制备和研究新型高压固态电池。本文重点研究了橄榄石型结构材料LiMPO 4（M=Fe，Co，Ni），其中通过用Co取代Fe来增加电压窗口（4.8 V）和Ni（> 5五.应处理下列科学问题：a）LiCoPO 4和LiNiPO 4是否为橄榄石-型阴极材料在脱锂作用下是化学稳定的，并且它们是否适用于高达尚不清楚的本征电压的高电压应用限制？B）LiCoPO 4和LiNiPO 4是否与氟代碳酸亚乙酯等典型电解质化学相容，橄榄石/电解质界面在5 V左右的电压下是否稳定？c）LiCoPO 4和LiNiPO 4是否与固体电解质化学相容（如e. G. LIPON）？薄膜阴极材料及其界面将在超高真空条件下制备，其电子性质将主要通过电子能谱进行原位研究。有了这样一个新的表面科学方法应用在离子导体，我们将解决的内在和外在的稳定范围的高电压橄榄石和研究可能的路线，以避免腐蚀性的副反应。