Composite battery separator (ACS application material interface 2013,5, 128- 134. ) is made of biomass cellulose and temperature-resistant polymer materials through low-cost nonwoven processing technology. Compared with the traditional polyolefin membrane, biomass cellulose as raw material has low cost and is environmentally friendly. At the same time, due to its unique polarity and chemical-physical structure, the diaphragm has good electrolyte wettability, high porosity and ionic conductivity, suitable mechanical strength and excellent high temperature resistance. Through the integrated innovation of diaphragm material design and molding process, the team solved the key technical problems of power battery diaphragm, built a low-cost, high-performance industrial technology system of power battery diaphragm, and authorized three patents in the fields of material preparation and core equipment.
It is of great significance to develop a low-cost intrinsically flame-retardant composite diaphragm system to improve the safety performance of power batteries. The poly (aryl sulfone amide)/sodium alginate/silica composite membrane developed by the team has high porosity and electrolyte absorption rate, excellent flame retardancy and high temperature resistance (J. Electrochem. SOC。 ，20 13， 160 (6)，A769-A774)。 Lithium-ion batteries assembled with poly (aryl sulfone amide)-based composite membranes can even be charged and discharged quickly at 65438 0 20℃. Polyarylsulfone amide-based composite separator is especially suitable for high-safety power lithium-ion batteries. This separator technology with independent intellectual property rights will promote the development of high-end battery separator industry in China.
Oil-based adhesives (such as polyvinylidene fluoride) are widely used in the production of lithium-ion battery pole pieces. However, a large amount of dimethyl pyrrolidone is needed as a solvent when preparing slurry, which leads to high production cost, environmental pollution, low Young's modulus, high brittleness, poor flexibility and low tensile strength. The electrode sheet prepared with this binder is easy to fall off, and the internal stress of the electrode sheet is also easy to produce cross sections and cracks during charging and discharging. Marine biomaterials, such as seaweed polysaccharide and chitin, have excellent bonding properties, but their film-forming properties are not good. The team developed a new type of high-performance marine biological water-based adhesive by functional modification of marine biological materials to improve film forming and electrochemical stability. The binder has high elastic modulus, is economical and environment-friendly, and can bear the expansion and contraction of active material particles to a certain extent during the electrode cycle, and is especially suitable for silicon-based electrode materials with high energy density and cathode materials with high potential. The research and development of high-stability water-based adhesive materials provides important raw materials and technical support for the green production process of lithium power batteries, and plays an important supporting role in the development of blue industrial clusters. At present, the research has applied for four invention patents.
Lithium hexafluorophosphate in traditional electrolyte has harsh preparation conditions, high cost, poor thermal stability and is extremely sensitive to water. The team designed and synthesized a new type of bio-based polymeric lithium borate (electrochimacta 2013,92, 132- 138). ) has excellent heat resistance, high lithium ion mobility and ionic conductivity, which provides a high-temperature resistant and safe electrolyte system for the development of power batteries. The polymer electrolyte can greatly improve the safety performance of the battery. This research has applied for two invention patents.
Based on the technical progress of high-performance separator, binder and electrolyte salt, a high specific capacity metal nitride composite material with good lithium intercalation performance is used as electrode material, and advanced pre-embedding technology is adopted to optimize the composition of trace additives in electrolyte, supplemented by self-developed separator, so as to reduce the internal resistance of capacitor, improve the interface stability of electrolyte/separator, improve the cycle performance of supercapacitor, and build a high energy density supercapacitor. An environment-friendly energy storage battery (JMaterchem, 20 12, 22,24918; J. Mater Chem A，20 13， 1，5949； ACS Nano，20 13，DOI: 10. 102 1/nn 40 1402 a)。 At present, the team is optimizing the structure of capacitor devices, hoping to develop lithium-ion capacitor energy storage devices with better performance. The research in this field has been authorized by four invention patents.
The above research has been supported by the Nano Pilot Project of Chinese Academy of Sciences, the "973" and "863" scientific and technological projects of the Ministry of Science and Technology, the National Natural Science Foundation and enterprises.