Influence of the fluoroethylene carbonate on the electrochemical behavior of Bi3Ge4O12 as Lithium-ion anode

Jassiel R Rodriguez; Carlos Belman-Rodriguez; Sandra B Aguirre; Sergio A Aguila; Vilas G Pol

doi:10.1016/j.jcis.2022.05.126

Influence of the fluoroethylene carbonate on the electrochemical behavior of Bi₃Ge₄O₁₂ as Lithium-ion anode

J Colloid Interface Sci. 2022 Dec:627:64-71. doi: 10.1016/j.jcis.2022.05.126. Epub 2022 May 25.

Authors

Jassiel R Rodriguez¹, Carlos Belman-Rodriguez², Sandra B Aguirre³, Sergio A Aguila⁴, Vilas G Pol⁵

Affiliations

¹ Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA; Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, BC 22860, Mex. Electronic address: jas_ciel@hotmail.com.
² Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, BC 22860, Mex; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC 22860, Mex.
³ Universidad Autónoma de Baja California, Unidad Ensenada, Ensenada, BC 22860, Mex.
⁴ Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC 22860, Mex.
⁵ Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.

PMID: 35841709
DOI: 10.1016/j.jcis.2022.05.126

Abstract

Systematic ex-situ X-ray diffraction (XRD) characterization and electrochemical study revealed the key roles that the cut-off voltage and fluoroethylene carbonate (FEC) additive play on improving electrochemical performance of the Bi₃Ge₄O₁₂-based (BGO) electrode. The ex-situ XRD analysis revealed that BGO particles suffer multiphase transitions during the (dis)charge reactions, being observed some phases as Bi₂O_2.33, BiLi₃, Li₂O, Ge₄Li₁₅, Ge₂Li₇, Ge₃Li₇, Ge₅Li₂₂, Ge₄Li₉, Bi₂O₃ and GeO₂. The electrochemical evaluation exhibited that the addition of 5 v/v% of FEC in 1.0 M lithium hexafluorophosphate (LiPF₆) in ethylene carbonate and diethyl carbonate (EC: DEC) at an applied cut-off voltage (1.5 V vs Li/Li⁺) improves the specific capacity (29%, delivering 479 mAh g^-1), capacity retention (12%) and rate capability (369 mAh g^-1 at 1000 mA g^-1) of the BGO-based electrode. Also, FEC promotes the formation of a stable solid-electrolyte interface (SEI) layer on the anode at a cut-off voltage of 1.5 V vs Li/Li⁺. It displays the lowest values of SEI and charge transfer (CT) resistances, and electrode polarization, improving the reversibility of the alloying reactions related to Ge-Li and Bi-Li and maintaining their redox activity after 100 cycles, according to dQ dV^-1 data.

Keywords: Anode; BGO-based electrode; Cut-off voltage; FEC additive; High performance; Li-ion battery.