Analyzing the research progress of all solid state lithium ion batteries

Source: 2020 - 03 - 23 PM hits: time the research progress of all solid state lithium ion batteries on the market since 1991, lithium ion batteries due to its high energy density, long life time and attention. Has become an integral part of energy economy in the 21st century. However, lithium ion battery application in automobile, energy storage, and other areas of the large battery there are still some safety problems to be solved. Organic electrolyte of lithium ion battery is a volatile, flammable and explosive. ( 1] All solid state lithium ion battery fundamentally solved this problem, and has the advantages of large capacity, light quality, can complete the industrialization of all solid state lithium ion battery research is imminent. 1. An overview of all solid state lithium ion battery solid-state lithium battery is relative to the liquid lithium battery, refers to the structure does not contain liquid, all data is stored in the form of solid energy device. Specifically, it is composed of the positive data + negative data and electrolyte, and liquid lithium batteries is by the positive + + negative data of electrolyte and the diaphragm. The research progress of all solid state lithium ion batteries, lithium ion solid electrolyte data as the core component of all solid state lithium ion battery, is the core to realize its high function data, is also one of the bottlenecks that affect its practical application. Solid electrolyte development history has more than one hundred years, the discussion of the solid electrolyte materials have hundreds, as long as the solid electrolyte at room temperature or high temperature conductivity is greater than 3 s/cm can be applied in electrochemical power supply system, the vast majority of conductivity data value several orders of magnitude lower than the value, which makes the few solid electrolyte materials has practical application value. ( 2] 2. The research progress of solid electrolyte electrolyte battery as an important part of its function to a great extent, determines the battery power density, cycle stability, safety performance, high and low temperature performance and service life. Electrolyte evaluation index generally includes: ( 1) Ionic conductivity: ionic conductivity will affect the assembly volume resistance of the battery. For solid electrolyte, ionic conductivity at 10 - general requirements More than 4 s/cm. ( 2) To the divisor: refers to the electrolyte of lithium ion in the current through the share of. Ideally, the divisor is 1. If the removal rate is too low, negative ion will accumulate in the surface of electrode, which resulted in increased cell polarization and resistance. ( 3) Electrochemical window: working voltage range, the battery electrolyte demand with high electrochemical stability, otherwise will happen in the working process of decomposition, electrochemical window above 4 general requirements. 3v。 ( 3] The current research of solid electrolyte are oxide solid electrolyte, sulphide solid electrolyte, polymer solid electrolyte and solid electrolyte. Here is the solid electrolyte and its research progress is introduced in detail. The research progress of all solid state lithium ion battery 2. 1 oxide solid electrolyte oxide solid electrolyte according to material structure is divided into crystalline electrolytes and vitreous ( Amorphous) The electrolyte. Including the garnet crystals electrolyte solid electrolyte, perovskite li3xla2/3 - XTiO3 solid electrolyte, NASICON Li1 + xalxti2 - x ( PO4) 3 and Li1 + xalxge2 - x ( PO4) 3 solid electrolyte, etc. Glassy state electrolyte resistance by perovskite li3 - 2 xmxhalo solid electrolyte and lipid membrane of solid electrolyte. 2. 1. 1 [garnet solid electrolyte 4] Traditional garnet electrolyte for Li7La3Zr2O12 ( LLZO) 。 Garnet electrolyte at room temperature (cubic phase 10 - 3s /cm) Has high ionic conductivity, when in contact with the metal lithium is more stable than other types of electrolyte. It is a very promising electrolyte. At present, the garnet electrolyte faces two major problems: 1. Lithium content high, making it easier for the surface of the electrolyte and water and carbon dioxide in the air to produce lithium hydroxide and lithium carbonate, cause a large interfacial impedance, cell function is poor. 2. Garnet electrolyte of lithium metal wetting ability is poorer, uneven lithium ion accumulation in the process of circulation, prone to dendrite, there are serious security hidden danger.