Lithium-ion batteries and supercapacitors are two types of representative energy storage devices, which have different energy storage principles and characteristics. Lithium batteries have a high energy density (~250 Wh kg -1 ) but low power density (<1 kW kg -1 ), while supercapacitors have a high power density (~15 kW kg -1 ) but low energy density (<20 Wh kg -1 ). Beyond the energy storage limits of the above two types of energy storage devices, developing new electrode materials for energy storage devices with both high energy density and high power density is a challenging issue in the field of chemical energy storage.
Recently, a team of scientists from the New Materials and New Energy Application Research Team of the Shanghai Institute of Ceramics, Chinese Academy of Sciences researched the macroscopic preparation method of high-capacity few-layer mesoporous carbon electrode materials, and the large-capacity black titanium dioxide electrode has extremely fast Energy storage and discharge speed. A series of progress has been made in ultra-high rate capacitor energy storage materials and nanoporous niobium oxide-based single crystals, supporting the "capacitor + battery" energy storage.
Aiming at the low specific capacity of the electric double layer energy storage on the surface of carbon materials, the research team based on the early design of high specific capacity nitrogen-doped few-layer carbon mesoporous, in order to realize the macroscopic preparation of high-performance nitrogen-doped carbon-oriented, " Silicon atoms anchor active nitrogen", "silicon-boron/aluminum atoms synergistically regulate the type/content of active nitrogen", "propose magnesium-assisted regulation of pore structure" and other material design and preparation ideas, and propose "sol-gel bonding glue-heat treatment A new method for large-scale preparation of nitrogen-doped disordered mesoporous few-layer carbon", the prepared nitrogen-doped carbon material has a conductivity of 150S/cm, a specific capacitance of 690F/g, a second cycle capacity, and a retention rate of 90% , has applied for a number of national invention patents, and related achievements have been published in J. Chem., ACS Appl. . , & .
Aiming at the problem that traditional metal oxide large-capacity energy storage is difficult to achieve high-power energy storage, the research team used the previous concept of quantum capacitance to illustrate the surface quantum polarization capacitance at the mesoporous/nanopore scale, combined with the density functional calculation of the density of the state distribution. , found that active nitrogen-doped titania has a new electricity storage mechanism of proton-coupled electron reaction. Based on the previously invented method of "low-temperature reduction + element doping" to prepare highly conductive black titanium dioxide, it was found that the high-concentration doped black TiO 2-x: N specific capacitance of 9.29 at% was as high as 750 F/ g, and changing the wide bandgap semiconductor titanium dioxide could not Apply to conventionally understood supercapacitor electrodes. Related results were published in Sci.
Aiming at the problem of poor rate performance of lithium battery anode materials, the research team proposed the design idea of a "pore + single crystal" porous single-crystal structure that can realize the rapid migration of "ion + electron", and integrated the bulk phase and surface with high energy storage and extremely Fast charging and discharging. Excellent performance. Based on the previous work of simulating the hydrothermal alteration in nature, this study invented the atomic scale micro-dissolution method, combined with high temperature and low oxygen partial pressure to induce oxygen defects, and successfully prepared nanoporous single crystal black Nb 2 O 5-x with high specific surface area. The specific capacity of lithium storage is /g, and the capacitance capacity is as high as 87%. It has extremely high rate performance (187 mAh/g@25C@4000 cycles, /g@250C), and its specific capacity and rate characteristics are far superior to those of oxides. The best-performing "zero-strain" Li 4 Ti 5 O 12 material has verified that the nanoporous single-crystal structure has high energy storage and excellent characteristics of the fusion bulk phase and the surface of extremely fast charge and discharge, realizing macroscopic energy storage at ultra-high rates The preparation and application of the device have achieved ultra-high rate storage at 200C and high energy density per kg. Related results are published in.
Relevant research has been funded and supported by projects such as the National Key R&D Program and the Innovation Team in Key Fields of the Ministry of Science and Technology. Related achievements "Structural design and performance regulation of high-performance electrode materials for high-power energy storage applications" won the first prize in the 2019 Shanghai Natural Science Award.
Design and preparation of silicon atom-anchored active nitrogen and its ultrahigh specific capacitance performance
Nitrogen-doped black titanium dioxide and its electrochemical performance as an active material for supercapacitors
Design, preparation, and electrochemical performance of ultra-high-magnification nanoporous single-crystal niobium oxide electrode materials