The top international journal Advanced Materials published the results of Professor Hu Ning's team: "Ceramic Medium -high Concentration ion Gel" solid electrolyte help high -pressure lithium metal battery

Recently, the team of Professor Hu Ning has achieved new research results in the field of lithium batteries and published it at the top international journal Advanced Materials (Doi: 10.1002/ADMA.202205560).

Traditional lithium batteries contain a large number of organic liquid electrolytes, which have hidden dangers of fire or even explosion, and have low energy density, which is difficult to meet the requirements of emerging strategic industries such as aerospace and new energy vehicles. The use of solid electrolytes replaced with electrolytic liquids and developed solid -state batteries is a new type of energy storage technology. It is expected to solve the safety problem of traditional lithium batteries, and can improve the energy density of battery, which is applied to the field of new energy vehicles. As the core material of solid -state batteries, the development of solid electrolytic materials with high room temperature ion conductivity, large ion migration, negative metal, and high -voltage positive compatibility has very important research significance.

Professor Hu Ning, Associate Professor Song Shofeng of Chongqing University, and Professor Yang Yong of Xiamen University, etc., designed and studied a "SuperConcentrated Ionogel –ceramic" (SIC) solid state through the original heat caused by the original heat. Electrolysis. This electrolyte not only shows the ultra-high room temperature lithium-ion conductivity (1.33 × 10-3 S CM-1), but also has 0.89 ultra-high lithium ions migration, and the electrochemical window is 5.5 V, which matches the metal lithium negative electrode and NCM523 The solid -state battery of LIFEPO4 shows excellent cycle stability.相关工作以“Enabling High–Voltage “Superconcentrated Ionogel–in–Ceramic” Hybrid Electrolyte with Ultrahigh Ionic Conductivity and SingleLi+–ionTransference Number”为题发表在国际顶级期刊Advanced Materials（DOI: 10.1002/adma.202205560）上。 The first author is Zhai Yanfang, a doctoral student of Chongqing University, Professor Hu Ning, our university, Associate Professor Song Shofeng of Chongqing University, and Professor Yang Yong of Xiamen University as the communication author of the paper.

In this study, by organically combining the mechanical (LLZO) electrolyte nanoparticles and high-concentration ion gel (3M Litfsi-EMIMFSI-PMMA), a high-voltage monocial conductive "ceramic medium high concentration ion gel" (SIC "(SIC ) New solid electrolyte. At the same time, the in -situ aggregation method is used to solve the problem of non -mixed solubility and interface problems of polymer in ionic gel in ionic liquid. The preparation process is shown in the figure below. Compared with the commercial PP diaphragm, the prepared SIC electrolyte has higher heat resistance (Figure C).

Figure 1 (a) PMMA free radical aggregation reaction. (B) design schematic diagram of SIC electrolyte.

(C) Comparison of the heat resistance of SIC electrolyte and commercial PP diaphragm.

Electrolyte is one of the key components of the battery. It can not only separate the cathode and anode, but also transport ions. The intense chemical interaction on the interface of ceramics and high-concentration ion gel leads to a integrated structure, which makes the electrolyte showing a high ion conductivity of 1.33 × 10-3 S CM-1 at room temperature to meet the actual application requirements of electrolytes. The ion conductivity at minus 30 ° C is still 1.68 × 10-5 S CM-1, which is better than most electrolyte materials. And the electrolyte chemical window is 5.5 V, the electronic conductivity is only 3.14 × 10−10 S CM−1, and the migration of Li ions is as high as 0.89. The electrolyte has broad prospects in the application of lithium metal batteries.

Figure 2 (a) SIC electrolyte and high -concentration ion gel room temperature AC radical spectrum.

(B) The conductivity of SIC electrolyte and high-concentration ion gel-temperature curve.

(C) SIC electrolyte DC polarization curve.

(D) Linear scanning vilules of SIC electrolyte and high -concentration ion gel.

(E) The current time of SIC electrolyte symmetrical battery-curve.

(F) The current time of the symmetrical battery of the high concentration ion gel-curve.

Figure 3 (A) LIflifepo4 The capacity of a solid-state battery-voltage curve.

(B) The cycle of li‖lifepo4 solid -state battery.

(C) The capacity of li‖lini0.5CO0.2MN0.3O2 solid-state battery-voltage curve. (D) LI‖lini0.5CO0.2MN0.3O2 solid-state battery cycle.

(E) SIC/NCM523 interface SEM/EDS diagram.

The compound electrolyte is formed through the in situ aggregation of the liquid front drive, which can solve the problem of high interface resistance between the electrolyte and the electrode. The research team uses the advantages of ceramics and ultra -concentrated ion gel, including good lithium metal stability and stable electrolyte/positive cross section to assemble LI‖NCM523 and Li‖lifepo4 solid -state batteries. Under the condition of 1C, it is stable to work for 300 laps, and Kuron's efficiency is close to 100%. The good cycle of the Li‖NCM523 battery in the room mild 1C indicates that the electrolyte can be matched with the high -voltage (4.3V) positive electrode material. From the SEM diagram, it can be seen that SIC electrolyte is closely integrated with NCM523. From the EDS diagram of N and F, it can be seen that ion gel infiltrates inside the positive electrode material, resulting in low interface resistance. Therefore, this "ceramic medium high concentration ion gel" solid electrolyte provides a new way for high -safety, high -energy density lithium metal batteries. The research work has been funded and supported by Hebei Province's key research and development plan, Hebei Province Natural Science Foundation Innovation Research Group, and Tianjin Science and Technology Plan.

Article link: https://doi.org/10.1002/adma.20220556

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