Bifunctional effect of laser-induced nucleation-preferable microchannels and in situ formed LiF SEI in MXenes for stable lithium-metal batteries. Issue 28 (9th July 2020)

• Record Type: Journal Article
• Authors: Xiong, Cheng; Wang, Zhenyu; Peng, Xudong; Guo, Yang; Xu, Shaolin; Zhao, Tianshou
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 28(2020)
• Page Start: 14114
• Page End: 14125
• Publication Date: 2020-07-09
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta04302h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A bifunctional effect of laser-induced aligned lithiophilic microchannels and in situ formed LiF-enriched SEI on lithium deposition is proposed by using fs laser on the MXene membrane. Stable Li plating/stripping is achieved at 20 mA cm −2 in an asymmetric cell. Abstract : Lithium (Li) metal is considered to be the ultimate choice of anode for high energy density lithium-based batteries. However, the uncontrollable dendrite growth, in particular at large current rates, hinders its practical applications. Herein, a novel MXene/TiO2 membrane with aligned microchannels as the lithium host is fabricated using a femtosecond laser, with numerous lithiophilic sites (TiO2 ) spatial-precisely synthesized on the channel walls. Benefiting from the exposed nanometer-scale edges of the MXene, a favorable Li + ion migration into the channels is achieved by the well-manipulated electric field, thus resulting in preferential Li deposition inside the microchannels. Moreover, a lithium fluoride (LiF) reinforced SEI is generated on the top surface of the host upon electrochemical cycling thanks to the built-in fluorine terminals in the MXene. As a result, a long lifespan of 750 cycles (1500 hours) with a coulombic efficiency of 98.8% is achieved at 1 mA cm −2 . Even at an ultrahigh current density of 20 mA cm −2, a lifespan of 500 cycles with a coulombic efficiency of 95.9% is still delivered.