In recent years, wearable, portable electronic devices, and MEMS (such as micro-robots, micro-sensors) are rapidly developing toward the direction of lightweight, small size and multi-function integration, which has greatly promoted the high power density and high energy density of modern society. Demand for micro-energy storage devices characterized by flexibility, modular integration, etc. Traditional lithium-ion capacitors have attracted attention because of their high energy density and the high power density of supercapacitors. However, they have a sandwich stack structure. The device configuration greatly limits its mechanical flexibility, high temperature performance, and modular integration capabilities.
Recently, the research team has taken the lead in the international development of a new concept of all-solid-state flexible planar lithium-ion micro-capacitors. The micro-capacitors use highly conductive graphene as a current collector and high-voltage ion gel as an electrolyte, and nano-titanic acid. Lithium is a negative electrode and activated graphene is a positive electrode to construct a high-ion-electron-conducting interdigitated microelectrode, and then an all-solid-state lithium ion micro capacitor is assembled on a substrate. The lithium ion microcapsule has a high energy density of 53.5 mWh/cm 3. , Higher than currently reported lithium thin-film batteries and micro-supercapacitors. At the same time, the lithium-ion micro-capacitors have excellent cycle stability, capacitance retention after 98 cycles is 98.9%; with high-temperature electrochemical stability, can be at 80 degrees Stable operation under C conditions; and excellent mechanical flexibility, achieving no degradation in performance under various bending and twisting conditions. In addition, the lithium ion micro-capacitors exhibit good modular integration capability without the need for metallic connectors. The output voltage and capacity are regulated. Therefore, this work is to develop flexible, miniaturized, intelligent energy storage. The device provides a new strategy.
The above work has been funded by the National Natural Science Foundation of China, the National Key R&D Program, and the National Youth Project.
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Dalian Institute of Materials Research progresses in the research of all-solid-state flexible plane lithium ion micro-capacitors