【作者】 谭国强；

【导师】 吴锋；

【作者基本信息】 北京理工大学 ， 环境工程， 2014， 博士

【摘要】 本文重点综述了固态化锂电池及相关电极与电解质材料的研究进展。固态化锂二次电池具有比常规液态锂离子电池更高的比能量，且由于电池中几乎不含有液态电解质，对解决液态锂离子电池在非常规环境下可能产生的漏液、易燃、易爆等安全性问题，具有重要意义。固态化电解质的应用能简化电池结构，使电池的形状尺寸具有更灵活的可设计性。随着便携式电子设备和电动汽车日益增长的对高能量、高功率和高安全性需求的发展，固态化锂二次电池已成为国际研发的热点之一。开发新型薄膜电极和固态化电解质材料，优化电池结构设计是发展高性能固态化锂二次电池的基础。本文从开发制备新型电极和电解质材料入手，结合它们的物化特性，优化设计出新型固态化电池构造，首次制备出高安全性的固态化锂离子电池，继而研制出高比能和高安全性的固态化金属锂电池，实现了从固态化锂离子电池到固态化金属锂二次电池的技术转化；研究新材料，探索新概念，开发新体系，发展新技术，推动固态化锂二次电池的发展，实现规模化生产与应用，从而为进一步发展全固态锂二次电池奠定技术基础。本文围绕开发新型高性能固态化锂二次电池进行了系统的研究工作，主要取得了以下阶段性成果和进展。(1)采用磁控溅射技术制备出新型三元电极薄膜，用作固态化锂电池正极。通过射频磁控溅射在高纯氩气或氧-氩混合气中制备了三元正极薄膜，通过控制退火温度和时间，生成了一系列具有不同结晶度和欠锂化学组分的薄膜。预沉积薄膜为无定型态，具有高的化学扩散系数，表现出较好的电化学性能，这种薄膜电极适应于小电流微型电子设备，可应用于薄膜锂电池；高温退火薄膜具有稳定的晶体结构、欠锂化学组成、纳米粒子生长及微米厚度设计，表现出独特且良好的电化学性能，这种薄膜电极具有高的能量密度，适用于高比能锂电池正极材料，可应用到固态化锂电池。(2)采用磁控溅射技术制备出新型玻璃态磷酸锂包覆磷酸铁锂电极，可作为固态化锂电池正极。以磷酸锂为靶，磷酸铁锂电极为基片，通过射频磁控溅射制备了磷酸锂包覆磷酸铁锂复合电极，通过调节溅射功率和沉积时间，制备了一组具有不同包覆形貌的复合电极。包覆的磷酸锂薄膜是一种良好的锂离子导体，具有玻璃态结构本质，与磷酸铁锂电极形成珊瑚状多孔交联网络结构，促进了电极的离子和电子的传输，提高了界面电荷传质效率，改善了电极的结构稳定性。这类电极具有高的比容量和良好的功率特性，可应用于锂动力电池。(3)采用反应磁控溅射法制备出Li-Al-Ti-P-O-N薄膜电解质，用于全固态薄膜锂电池。以NASICON结构的Li Al Ti P O化合物为靶材，通过射频磁控溅射法在高纯氮气中制备了新型的Li-Al-Ti-P-O-N薄膜，通过改变沉积温度制得了一系列的薄膜。研究发现氮参杂取代了部分氧原子，降低了反应活化能，形成了更丰富的交联网络结构，促进了锂离子的传导；高温沉积提高了薄膜的结晶度，形成晶态-非晶态混合结构，同样有利于锂离子的传导。这类薄膜电解质具有较高的离子电导率和良好的电化学稳定性，可作为全固态薄膜锂电池用新一代电解质材料，未见文献报道。(4)采用溶胶-凝胶法合成出新型固态化介孔二氧化硅/离子液体复合电解质，并首次组装成固态化锂离子电池。复合电解质由多孔二氧化硅骨架原位吸附离子液体电解质组成，其中二氧化硅起支撑作用并吸附大量离子液体，离子液体被分散在孔道网络中，具有流体特征，作为锂离子的传导介质。复合电解质表现出接近液态电解质的高离子传导率和良好的电化学稳定性，它们还具有良好的热稳定性、化学稳定性和机械强度，成为一种新型高性能固态化电解质材料。利用复合电解质组装形成的新型固态化锂离子电池能正常工作，表现出良好的电池性能。(5)采用原位组装技术设计制备出新型固态化金属锂二次电池，完成了从固态化锂离子电池到固态化金属锂二次电池的技术转化，实现了金属锂电极的安全利用。这种固态化锂电池具有全新电池结构设计，表现出良好的电池综合性能，在实际应用中具有诸多优点：相比传统固态化电池体系，表现出更高的比能量和比功率；具有不漏液、耐高温、抗冲击和防止锂枝晶生长等的高安全性；原料丰富，制备简单，成本低廉，具有灵活的可设计性，易实现规模化生产；高效节能，绿色环保。这种新型固态化电池构造，为固态化锂电池技术的发展提供了新的科学思路，并对固态化锂电池的发展应用具有一定的促进作用。更多还原

【Abstract】 This paper reviewed the research progress in solid-state lithium batteries and relatedelectrode and electrolyte materials. Solid-state rechargeable lithium batteries provide asignificantly higher energy than that offered by conventional lithium ion batteries whichcontain organic electrolytes. They scarcely contain any liquid electrolytes, so they can offera fundamental solution for the safety of conventional lithium ion batteries. The applicationof solid-state electrolytes simplifies the battery structure, and makes the battery shape andsize have more flexible design. With the development of portable electronic devices andelectrical vehicles, the growing demand for renewable energy technologies with higherenergy, higher power and better safety are required, the solid-state rechargeable lithiumbatteries are believed to be novel green renewable power sources, and have become a hottopic in the international development. Developing novel thin film electrode and solid-stateelectrolyte materials, and optimizing battery structural design are the basis for thedevelopment of high-performance solid-state rechargeable lithium batteries. In this study,we started from the preparation of new electrode and electrolyte materials, combined theirphysical and chemical properties, and designed novel solid-state battery configurations. Wefirstly prepared a new solid-state lithium ion battery with high safety, then developed a newsolid-state lithium metal battery with high energy density and high safety, realized thetechnical transformation from the solid-state lithium ion battery to solid-state rechargeablelithium metal battery. We researched new materials, explored new concepts, exploited newsystems and developed new technologies, attempted to promote the development ofsolid-state rechargeable lithium batteries, realize their production and application of scale,and lay a technical foundation for the further development of all-solid-state rechargeablelithium batteries. In this paper, we carried out systematic research work based on thedevelopment of new high-performance solid-state rechargeable lithium batteries, andobtained main achievements and progress as follows:（1） Li Co Ni Mn O thin film electrode was prepared by magnetron sputtering forthe first time and would be used as the cathode for solid-state lithium batteries. TheLi Co Ni Mn O thin films were prepared by radio-frequency magnetron sputtering usinga LiCo_1/3Ni_1/3Mn_1/3O₂target in the high-purity Ar or Ar-O₂atmosphere. Thin films wereannealed at different temperatures for different times to generate various crystalline and chemical compositions. The as-deposited thin film had an amorphous structure with highchemical diffusion coefficient, and exhibited good electrochemical performance. It wassuitable for the micro-electronic devices with small current, and would be applied to thinfilm lithium battery. The annealed thin film possessed stable crystal structure, delithiatedchemical composition, nanosized particle growth and micron thickness design. It exhibitedunique and excellent electrochemical performance, and had high energy density, wassuitable as the cathode material for high energy lithium batteries, and would be applied tosolid-state lithium batteries.（2） Novel coralline glassy lithium phosphate-coated LiFePO₄electrode was preparedby magnetron sputtering, and would be used as the cathode for solid-state lithium batteries.The composite electrodes were prepared via radio-frequency magnetron sputtering a Li3PO₄target onto the LiFePO₄electrodes in a high-purity Ar. A series of composite electrodes withdifferent coating morphologies were obtained by adjusting the sputtering power anddeposition time. The lithium phosphate coating was a good Li+conductor, it had glassystructure and stacked well on the electrode to form a coralline surface with mass porouscrosslinked networks, which promoted the ionic and electronic transport on the electrode,improve the electrode-electrolyte interfacial charge transfer efficiency, and improve theelectrode structural stability. This kind of electrode possessed high capacity and powercapability would be used as the cathode for lithium ion power batteries.（3） Li-Al-Ti-P-O-N thin film electrolyte was prepared using a reactive magnetronsputtering technology for the first time, and would be applied to all-solid-state thin-filmlithium batteries. The Li-Al-Ti-P-O-N electrolytes were prepared by radio-frequencymagnetron sputtering deposition using a NASICON structural Li Al Ti P O target in ahigh-purity N2at various deposition temperatures. The study found that the substitution ofnitrogen for oxygen in the thin film created abundant crosslinking structures and decreasedthe activation energy, which favored the higher mobility of lithium ions. High temperaturedeposition improved the crystalline of thin films, forming a crystalline-amorphous mixedstructure, which was also beneficial for lithium ionic conduction. This kind of thin filmelectrolyte possessed good electrochemical properties is a promising candidate material forall-solid-state thin-film lithium batteries. It has not been reported in the literature.（4） A novel solid-state composite electrolyte based on mesoporous silica matricesin-situ immobilizing ionic liquids was synthesized by a sol-gel method, and was assembledinto solid-state lithium ion batteries for the first time. Composite electrolytes consisted of porous silica matrices and confined ionic liquids, the silica matrices imparted mechanicalstability and provided a porous environment to absorb large amounts of ionic liquids,though the ionic liquid electrolytes were dispersed in porous silica matrices, they exhibitedhigh fluid-like dynamics, and acted as the transmission medium of lithium ions. Therefore,composite electrolytes exhibited high ionic conductivity and good electrochemical stabilityclose to the liquid electrolytes, and also had good thermal stability, chemical stability andmechanical strength, have become a new high-performance solid-state electrolyte material.The novel solid-state lithium ion batteries using composite electrolytes could operatenormally, and showed good battery performance.（5） Novel solid-state rechargeable lithium metal battery with solid-state compositeelectrolytes was designed and prepared by using an in-situ self-assembly technology. Itrealized the technical transformation from solid-state lithium ion batteries to solid-staterechargeable lithium metal batteries, and allowed the safe use of a lithium metal electrode.This kind of lithium battery had a new solid-state battery structural design, and exhibitedgood comprehensive properties. It had many advantages in practical applications: i) highenergy density and high power density in a solid-state battery system; ii) good safetyassociated with its no leakage, high temperature resistance, impact resistance, andprevention of lithium dendrite growth; iii) abundant raw materials, low cost, various designpossibilities for configuration, simple manufacture and easy for large-scale production; iv)high efficiency, energy saving, and environmental benignity. This new type of solid-statebattery configuration would provide new ideas for the development of solid-state lithiumbattery technologies, and play a great role in promoting the development and application ofsolid-state lithium batteries.更多还原