A Computational Comparison of Ether and Ester Electrolyte Stability on a Ca Metal Anode

作     者：Diana Liepinya Manuel Smeu 

作者机构：Department of PhysicsBinghamton UniversityBinghamtonNYUSA Department of Materials Science and EngineeringUniversity of MarylandCollege ParkMDUSA 

出 版 物：《Energy Material Advances》 (能源材料前沿（英文）)

年 卷 期：2021年第2021卷第1期

页      面：24-36页

核心收录：

学科分类：07[理学] 070303[理学-有机化学] 0703[理学-化学] 0702[理学-物理学] 

基　　金：the National Science Foundation Research Experiences for Undergraduates Program(DMR-1950555). 

主　　题：electrolyte backbone realization 

摘      要：Ca-ion batteries(CIBs)have the potential to provide inexpensive energy storage,but their realization is impeded by the lack of suitable electrolytes.Motivated by recent experimental progress,we perform ab initio molecular dynamics simulations to investigate early decomposition reactions at the anode-electrolyte interface.By examining different combinations of solvent—tetrahydrofuran(THF)or ethylene carbonate(EC)—and salt—Ca(BH_(4))_(2),Ca(BF_(4))_(2),Ca(BCl_(4))_(2),and Ca(ClO_(4))_(2)—we identify a variety of behavioral trends between electrolyte solutions.Next,we perform a separate trajectory with pure THF and gradually increased negative charge;despite an addition of-32e,no THF decomposition is detected.Charge analysis reveals that in a reductive environment,THF distributes excess charge evenly across its hydrocarbon backbone,while EC concentrates charge on its ester oxygens and carbonyl carbon,resulting in decomposition.Graphs of charge vs.time for both solvents reveal that EC decomposition products can be reduced by up to five electrons,while those of THF are limited to a single electron.Ultimately,we find Ca(BH4)2 and THF to be the most stable solution investigated herein,corroborating experimental evidence of its suitability as a CIB electrolyte.