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Influence of electrolyte constitution on metal dissolution and surface free energy correlation

Title
Influence of electrolyte constitution on metal dissolution and surface free energy correlation
Translated Title
금속 용출에 관한 전해액 구성에 대한 영향과 표면자유에너지와의 관계
Authors
Choi, Sung Mo
DGIST Authors
Choi, Sung Mo; Lee, Ho Chun; Kim, Jae Hyeon
Advisor(s)
Lee, Ho Chun
Co-Advisor(s)
Kim, Jae Hyeon
Issue Date
2015
Available Date
2015-01-12
Degree Date
2015. 2
Type
Thesis
Keywords
금속용출표면자유에너지LiMn2O4LiNi0.6Co0.2Mn0.2O2전해액
Abstract
One of promising cathode for lithium ion battery is LiMn2O4 (LMO) due to its low cost and environmental inertness. However, LMO suffers from Mn dissolution followed by cell degradation. Mn-dissolution is heavily affected by electrode surface and electrolyte, so it is electrode/electrolyte interfacial phenomenon. However, more methodical research about the relationship between the electrolyte property and Mn-dissolution has not been carried out so far. This study examine the dependence of the Mn-dissolution on electrolyte constitution at various temperature and its kinetics. The Mn2+ ion concentration in the electrolyte at vari-ous temperature storage was analyzed by using atomic absorption spectroscopy (AAS). It was revealed that increasing EC content, storage duration and elevated temperature acceler-ates Mn-dissolution. It is diffusion controlled through the product layer. When increasing EC content, it diminish the activation energy of dissolution on electrode/electrolyte interface. ⓒ 2015 DGIST
Table Of Contents
Ⅰ. Surface free energy measurement to assess metal dissolution behavior of layered oxide LiNi0.6Co0.2Mn0.2O 2 -- 1.1 Introduction 1 -- 1.1.1 Overview 1 -- 1.1.2 Theory of surface free energy calculation 2 -- 1.1.3 Capillary rising method for porous materials 8 -- 1.1.4 Examples of surface free energy usages to analyze the Li ion batteries 10 -- 1.2 Experimental 11 -- 1.2.1 Adsorption method 11 -- 1.2.2 Preparation of NCM electrode 14 -- 1.2.3 Metal dissolution 15 -- 1.3 Results and discussion 16 -- 1.3.1 Metal dissolution and SFE of Al coated LiNi0.6Co0.2Mn0.2O2 16 -- 1.3.2 Analysis of the morphology of Al coated LiNi0.6Co0.2Mn0.2O2 19 -- 1.3.3 Connection between SFE and metal dissolution of Al coated LiNi0.6Co0.2Mn0.2O2 20 -- 1.4 Conclusions 24 -- Ⅱ. Influence of the electrolyte constitution on the dissolution kinetics of manganese from LiMn2O4 cathode for lithium ion battery -- 2.1 Introduction 25 -- 2.2 Experimental 27 -- 2.3 Results and discussion 29 -- 2.3.1 Effects of EC content, reaction temperature and storage time on Mn dissolution 29 -- 2.3.2 Kinetics of Mn dissolution 31 -- 2.3.3 Chemical reaction controlled 33 -- 2.3.4 Diffusion controlled through the product layer 36 -- 2.3.5 Activation energy determination 39 -- 2.3.6 Effect of solvation energy and HF 41 -- 2.4 Conclusions 44 -- Ⅲ. Analysis of surface free energy in battery electrolytes. -- 3.1 Introduction 45 -- 3.2 Experimental 46 -- 3.3 Results and discussion 48 -- 3.3.1 Characterization of reference materials 48 -- 3.3.2 The surface free energy calculation of propylene carbonate 51 -- 3.4 Conclusions 53
URI
http://dgist.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000001922848
http://hdl.handle.net/20.500.11750/1402
DOI
10.22677/thesis.1922848
Degree
Master
Department
Energy Systems Engineering
University
DGIST
Files:
Collection:
Energy Science and EngineeringThesesMaster


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