Recently, new advance has been gained by Prof. Ying Bai’s Group from School of Physics and Electronics in our university, concerning the artificial regulating of Li⁺ transportation at cathode-electrolyte interface in Lithium-ion batteries (LIBs) utilizing unique piezoelectric material. A full research paper entitled “Local Electric-field-driven Fast Li Diffusion Kinetics at the Piezoelectric LiTaO₃ Modified Li-rich Cathode-electrolyte Interphase” has been published in the journal of Advanced Science. The first author Miss Mengting Si is a master student. Vice professor Huiling Zhao and professor Ying Bai are co-corresponding authors of this work.  

LIBs have been highly expected in electric vehicles (EVs), plug-in HEVs (PHEVs), mass energy storage system, and aerospace besides the traditional applications in portable devices. Despite the advantages of high energy density, high output potential, long cycle life and environmental friendliness, the challenges of structural stability and Li⁺ diffusion property at electrode-electrolyte interface significantly impeded the further application of LIBs. To address the above mentioned concerns, tremendous efforts have been paid on rationally design and construct effective interface layer to ameliorate the Li⁺ diffusion behavior at the interface.    

Schematic diagram of regulating ion kinetics at interface by piezoelectric material during one charge-discharge cycle.

In this work, a more “initiative” piezoelectric LiTaO₃ has been utilized to modify the surface of high-capacity Li-rich cathode. Accompanied by the deintercalation/intercalation of Li⁺ and the resulted respiration of crystal lattice upon cycling, extra stress will be transmitted to the LiTaO₃ coating layer. Thus generated local electric-field will expediate Li⁺ diffusion at the electrode-electrolyte interface, particularly in discharge process, besides enhancing the structure stability as a robust protection layer. This work provides an effective and facile strategy to artificially regulate and optimize the Li⁺ kinetics at the cathode-electrolyte interface, which contributes to the comprehension of interface engineering in a broad range of applications in the electrochemical and energy conversion community（DOI: 10.1002/advs.201902538）.

Advanced Science is an interdisciplinary premium open access journal covering fundamental and applied research in materials science, physics and chemistry, medical and life sciences, as well as engineering. In 2019, the Impact Factor increased by 27% to a value of 15.804 (2019 Journal Citation Reports).

Website: https://doi.org/10.1002/advs.201902538

In addition, Ying Bai’s group has advanced a surface doping & coating integrated modification strategy for designing and optimizing a more compatible solid electrolyte-active electrode solid-solid contact, through gradient doping the cations into the surface lattice of active cathode material from solid electrolyte. （Nanoscale, 2019, 11, 8967-8977; ACS Applied Materials & Interphases, 2019, 11, 16233-16242）

Website: https://pubs.rsc.org/en/content/articlelanding/2019/nr/c9nr01655d#!divAbstract

Website: https://pubs.acs.org/doi/10.1021/acsami.9b02996

These works were supported by the National Natural Science Foundation of China (51672069), the 863 program of China (2015AA034201), the Program for Innovative Research Team in Science and Technology in Universities of Henan Province (IRTSTHN) (201RTSTHN012), the Program for Science and Technology Innovation Talents in Universities of Henan Province (16HASTIT042).