TU-TESL

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In the past two years, the voice of solid state has become increasingly high. However, due to the problems of cost, safety and raw materials, large-scale mass production and mature application of solid-state batteries still have a long way to go. From the perspective of domestic enterprises, Qingtao energy, Huineng technology, Ganfeng lithium, 123rd, Weilan new energy, Jiawei Co., Ltd., Judian new energy and other lithium battery enterprises are all building solid-state battery production lines, some of which have even been put into production. By consulting patents, we found that in solid-state battery technology exploration, catl, Tianci materials, Tianjin Lishen, Zhuhai Guanyu, Shenzhen bick, Shenzhen Advanced Research Institute and Ningbo Materials Research Institute of Chinese Academy of sciences are the most prominent technologies. Among them, the typical representatives are the catl and the gifted materials. The patent for rigid diaphragm and solid-state lithium metal battery applied by Ningde times, on the one hand, uses metal lithium as anode, takes advantage of lithium specific capacity of 3860mah / g, electrochemical potential of - 3.04v, and its energy density is more than 400wh / kg. On the other hand, it solves the problems of safety and cycle life, effectively improves the cycle performance of solid-state lithium metal battery and reduces the probability of short circuit. The general implementation is shown in Fig. 1-fig. 2, and the steps are divided into four steps. The first step is to mix the active substance, sulfide solid electrolyte, conductive agent and adhesive styrene butadiene latex into THF solvent according to the weight ratio. Then coating the surface of the aluminum foil, drying at 60 ℃, cold pressing and slicing to obtain the cathode active material of LiCoO2 with a thickness of 50um. In the second step, sulfide solid electrolyte and binder are mixed with THF solvent according to the weight ratio. Then coated on the surface of glass and dried to get electrolyte film, sliced to get solid electrolyte film with thickness of 50um. In the third step, the aluminum foil is sliced into rigid membrane. Then the lithium metal is pasted on the surface of the copper foil and sliced into anode plates. In the fourth step, the cathode electrode, solid electrolyte membrane, rigid membrane and anode electrode are aligned with the lamination in order. Under certain conditions, the cell unit is obtained by cold pressing for 2min, and then the solid lithium metal battery is formed by laminating and packaging. This patent of Ningde era has the advantages of inhibiting the expansion or penetration of lithium metal anode into the solid electrolyte membrane and reducing the short circuit probability in the preparation of solid lithium metal battery. At the same time, the alloy formed by the deposition of lithium during the charging process of rigid film and solid-state battery can reduce the short circuit probability during the charging and discharging cycle, and improve the cycle stability of solid-state lithium metal battery. Figure 1 (rigid diaphragm structure) Figure 2 (solid-state lithium metal battery structure) Figure 3 (first cycle charge discharge curve of solid-state lithium metal) a patent for a solid-state battery preparation method applied by the God given material, which effectively improves the intrinsic characteristics and electrochemical performance of the battery, improves the ion conductivity of the solid-state electrolyte, and the preparation process is simple, repeatable and mass-produced, with significant application and promotion Value. The patent implementation steps of Tianci material are as follows: firstly, the positive electrode material lithium nicoaluminate is mixed with the solid electrolyte lithium sialuminate powder, then the film is formed by flowing with collodion glue, and the positive electrode plate is prepared by punching. Then, the solid electrolyte, lithium aluminosilicate, was cast into a film with collodion, and the solid electrolyte sheet was prepared by punching. The positive plate and solid electrolyte plate are stacked and sintered by hot pressing, and covered with lithium negative plate. After cold pressing, all solid battery with sandwich structure is formed. The combination of positive electrode and solid electrolyte by hot pressing means that both materials can bear certain heat. Hot pressing can make them contact more closely and reduce the interface impedance. The negative electrode is cold pressed, which is made of lithium metal or alloy with low melting point and ductility. The cold pressure makes the interface between the negative electrode and the solid electrolyte fully contact, and does not make them penetrate into the solid electrolyte to cause the battery short circuit. As shown in Figure 5, as an example of Tianci material patent, the first coulomb efficiency test shows that the charge discharge ratio is 0.1C and the electrochemical stability is good. Figure 4 (solid state battery) Figure 5 (an example of the first charge and discharge test) the patent of all solid state secondary battery of Shenzhen Advanced Research Institute can solve the existing problems of interface gap, interface resistance, interface instability and lithium dendrite growth of all solid state battery, with simple process and convenient for industrial production. The general implementation steps, as shown in Fig. 1, are to reduce the gap between the electrode material and the solid electrolyte layer and the high interfacial resistance by setting the gel polymer coating between the electrode and the solid electrolyte. At the same time, it can inhibit the side reaction and the growth of lithium dendrite, and the electrochemical performance is better. It is worth mentioning that the gel polymer coating material used in the patent is easy to get, environmentally friendly, simple in production process and low in cost. Figure 6 (1-negative layer 2-Polymer coating 3-solid electrolyte layer 4-positive layer) [1] a rigid membrane and solid lithium metal battery of Ningde era new energy [P]. China: cn109659474a 2019-4-19 [2] a solid state battery of Guangzhou Tianci high tech material and its preparation method [P]. China: cn110380116a 2019-10-15 [3] Shenzhen Advanced Research Institute All solid state secondary battery and its preparation process [P]. China: cn110518283a 2019-11-29 [4] electrodeposition and coating preparation method of Shenzhen Advanced Research Institute (Zuo Weifeng) [P]. China cn109423671a 2019-3-5