Collaborative Research: Tunable Control of Mixed Ionic and Electronic Conductivity through Ion Irradiation in Electroceramic Materials for Energy Storage System

非技术描述：这项基础研究的目标是显着提高锂离子电池的性能。这些电池是最有前途的储能技术之一，是可再生能源和电动汽车市场短期增长所急需的。本项目研究如何通过添加杂质或产生其他缺陷来故意改变电瓷材料（用于电池）。对于电极（即，阳极和阴极）材料，导电性对于高能量和高功率锂离子电池是关键的。最近的研究表明，当电极材料含有缺陷时，性能得到改善，有可能延长电池的能量、功率密度、稳定性、极端条件下的耐受性和日历寿命。该项目的重点是探索模型氧化物系统，二氧化钛（TiO 2），以揭示这些电瓷材料中的潜在导电现象。此外，该项目还与教育、多样性和培训活动相结合，这些活动被两所参与大学（博伊西州立大学和普渡大学）整合。例如，该项目正在实施一个跨机构的本科研究人员“交换”计划。技术支持：该研究提出了一种独特的方法，利用辐照来定制离子/电子电导率，这可能会在辐照增强材料功能方面开辟新的研究途径，并在定制电瓷材料的电化学性能方面取得前所未有的进步。该项目研究的假设是，辐照诱导的缺陷可以提供对电子陶瓷材料中混合离子/电子电导率的可调控制，从而为锂离子电池应用提供增强的电化学性能。含有外源性（例如，掺杂）和本征缺陷（例如，空位、阳离子无序）表现出改善的电化学性能。具体地，非本征缺陷可以增强电子电导率，而本征缺陷可以增强离子电导率。中能离子辐照产生本征缺陷，而辐照的离子种类作为非本征缺陷被注入靶材料中。因此，理论上，适当选择照射离子种类和能量能够调节离子和电子电导率以产生更好的电化学性质。该项目的重点是一种模型金属氧化物，TiO 2（TiO 2）。用铌离子辐照产生内在和外在缺陷的试样，与用氦离子辐照的试样相比，氦离子从靶材料扩散，只留下内在缺陷。该假设正在测试的结晶薄膜，这使得一个机械的理解中间能量照射对金属氧化物的影响形成。在此基础上，对多晶纳米结构TiO 2电极进行了研究，以阐明离子辐照对电极电化学性能的影响。这项研究正在纳入教学和推广模块，以便在两个参与机构之间进行整合，并通过NanoHUB提供。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

NON-TECHNICAL DESCRIPTION: The goal of this foundational study is to significantly improve the performance of lithium ion batteries. These batteries are among the most promising energy storage technologies and are much needed for near-term growth of the renewable energy and electric vehicle markets. This project examines how electroceramic materials (used in batteries) can be intentionally altered by adding impurities or producing other defects. For electrode (i.e., anode and cathode) materials, conductivity is critical for high energy and high-power lithium ion batteries. Recent research demonstrates improved performance when electrode materials contain defects, with the potential to extend battery energy, power density, stability, tolerance in extreme conditions, and calendar life. This project focuses on and explores the model oxide system, titania (TiO2) to shed light on the underlying conductivity phenomena in these electroceramic materials. In addition, this project is coupled to education, diversity, and training activities that are integrated across two participating universities (Boise State and Purdue). For example, this project is implementing a cross-institutional undergraduate researcher 'exchange' program.TECHNICAL DETAILS: This study presents a unique method for tailoring ionic/electronic conductivity using irradiation, which could open new research pathways in irradiation-enhanced materials functionality and lead to an unprecedented advancement in tailoring electrochemical performance in electroceramic materials. The project investigates the hypothesis that irradiation-induced defects can provide tunable control over the mixed ionic/electronic conductivity in electroceramic materials, thus delivering enhanced electrochemical properties for lithium-ion battery applications. Electrodes containing extrinsic (e.g., doping) and intrinsic defects (e.g., vacancies, cation disorder) exhibit improved electrochemical properties. Specifically, extrinsic defects may enhance electronic conductivity, while intrinsic defects may enhance ionic conductivity. Intermediate energy ion irradiation creates intrinsic defects, while the irradiating ion species becomes implanted in the target material as extrinsic defects. Thus, it is theorized that the appropriate selection of the irradiating ion species and energy enables tuning of the ionic and electronic conductivity to produce better electrochemical properties. This project focuses on a model metal oxide, TiO2 (anatase). Specimens irradiated with niobium ions to produce both intrinsic and extrinsic defects, are compared to specimens irradiated with helium ions, which diffuse from the target material and leave behind only intrinsic defects. The hypothesis is being tested on crystalline thin films, which enables a mechanistic understanding of intermediate energy irradiation effects on metal oxides to be formed. Building on these results, research on a polycrystalline nanoarchitectured TiO2 electrode follows to elucidate the ion irradiation effect on the electrochemical properties of the electrode. This research is being incorporated into teaching and outreach modules for integration across the two participating institutions and is being made available via NanoHUB.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.