Preparation And Performance Of The Novel Solid-State Rechargeable Lithium Batteries And Relative Materials

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.