Professor Guo Hang's research group has made new progress in the research on the preparation of micro thin-film lithium-ion batterie
Recently, Professor Guo Hang's research group at our institute has made new progress in the field of thin-film lithium-ion battery manufacturing. The relevant research results, titled "PVA-assisted spray deposited porous Li4Ti5O12 thin film as high-rate and long-cycle anode for lithium-ion thin-film batteries," were published in the international journal "Journal of Colloid and Interface Science" (Category 1 of the Chinese Academy of Sciences, IF=9.9).
Micro thin-film lithium-ion batteries are ideal energy storage devices for MEMS devices. However, the large-scale preparation of high-rate and long-cycle-life thin-film electrodes is very challenging, especially overcoming the cracking and detachment during the high-temperature crystallization process of the film. Professor Guo Hang's research group developed a new strategy for preparing porous Li4Ti5O12 thin-film electrodes by combining organic polymers with inorganic titanates, using ultrasonic spray deposition. This strategy uses the rich hydroxyl content of polyvinyl alcohol to change the evaporation process of the atomized droplets, significantly improving the uniformity of the film. Through the cross-linked network formed by titanium butoxide and polyvinyl alcohol, it dissipates the thermal stress during the high-temperature annealing process, solving the cracking and detachment issues during the high-temperature annealing of the film, and achieving the rapid preparation of high-quality porous crystalline films. The study shows that the 3D interconnected porous structure formed by the phase separation of the organic/inorganic composite film at high temperatures provides ample channels for the rapid transmission of electrons and lithium ions. Impedance analysis reveals that the Ti3+ formed during the lithiation process of Li4Ti5O12 can significantly improve the intrinsic conductivity of the electrode. Therefore, the prepared Li4Ti5O12 thin film exhibits excellent rate performance and ultra-long cycle stability. This work provides a new strategy for the preparation of thin-film electrodes. The work was completed under the guidance of Professor Guo Hang from our institute and Professor Zhang Ying from the Xiamen University Malaysia Campus. The first author of the paper is Doctoral student Lan Tu from our institute, a 2022-level student. The work was supported by the National Key R&D Program (2020YFB2007400).
