Electrician made progress in lithium ion capacitor anode pre-embedded lithium technology

[ Instrument Network Instrument R & D ] Recently, Ma Yanwei's team at the Superconducting and Energy New Materials Research Department of the Institute of Electrical Engineering, Chinese Academy of Sciences made progress in lithium ion capacitor anode pre-lithium technology, and related research results were published in the material journal Energy Storage Materials.

Li3N pre-lithium embedding process diagram

Lithium-ion capacitors are a new type of energy storage device between supercapacitors and lithium-ion batteries. They have the advantages of high energy density, high power density, fast charge and discharge, long cycle life and good safety performance. Electric vehicles, new energy generation, aerospace and defense and military have broad application prospects.

Pre-intercalation of lithium into the negative electrode is one of the key technologies for preparing high-performance lithium ion capacitors. This research innovatively proposed that Li3N with high specific capacity was used as a pre-intercalation agent for lithium-ion capacitors. For the first time, a dry process was used to prepare an activated carbon and Li3N composite positive electrode, and a soft carbon material was used as a negative electrode to assemble a flexible packaged lithium-ion capacitor. Li3N is completely decomposed into Li + and N2 after the first week of charging, Li + enters the negative electrode to complete the pre-lithium insertion process, and N2 is eliminated through the secondary sealing process without leaving non-electrochemically active materials. Based on the electrode material's energy density reached 74.7Wh / kg, power density reached 12.9kW / kg, and the capacity retention rate was 91% after 10,000 cycles. The method has simple operation process and high efficiency, and is easy to realize large-scale preparation of lithium ion capacitors.

The research team has carried out a lot of research work on large-scale preparation and application demonstration of lithium-ion capacitors in recent years, and achieved a series of research results. At the "2019 Supercapacitor Industry Annual Conference" held in November, its research results "China's self-developed full-carbon lithium-ion supercapacitors achieve demonstration loading operation" were selected by the China Supercapacitor Industry Alliance as "2019 China Supercapacitor Industry" One of the top ten events. "