I. INTRODUCTION 1 1.1 Background of energy storage and flow batteries 1 1.2 Principle and key components of ZBFB 4 1.3 Current status and shortcomings of ZBFB 5 1.4 Development of membranes for ZBFB applications 6 1.5 Cost evaluation of membranes in ZBFB system 10 1.6 Motivation and objectives of research 11 II. EXPERIMENTAL SECTION 12 2.1 Exploration of Low-cost SPEEK Membrane with Incorporated Perovskite-Structured Nanofiller Study: Future of Cost-effective Membrane Fabrication 12 2.1.1 Materials 12 2.1.2 Preparation of Cerium Titanate Nanoparticles Dispersed on Smooth Carbon Nanofibers (CTO@CNF) 12 2.1.3 Sulfonation of PEEK 13 2.1.4 Preparation of SPEEK-CTO Composite Membranes 13 2.2 Hydrophobic Organic Additive-Integrated SPEEK Blend Membrane Study: Scaling up for Large-Scale Battery Application 15 2.2.1 Materials 15 2.2.2 Dehydrofluorination of PVDF Process 15 2.2.3 Preparation of SPEEK-MD PVDF Blend Membrane 15 2.3 Characterization 16 2.3.1 Field-emission scanning electron microscope (FE-SEM) 16 2.3.2 Field-emission transmission electron microscope (FE-TEM) 16 2.3.3 X-ray diffractometry 16 2.3.4 Elemental analyzer 16 2.3.5 Chemical stability 17 2.3.6 Mechanical stability 17 2.3.7 Electrolyte uptake, Swelling ratio and Ion exchange capacity (IEC) 17 2.3.8 Oxidative stability 18 2.3.9 Area resistance and Ionic conductivity 18 2.3.10 Bromine permeability analysis 19 2.3.11 Ion selectivity 19 2.3.12 Measurement of zinc-bromine flow battery performance 19 III. RESULTS AND DISCUSSION 21 3.1 Exploration of Low-cost SPEEK Membrane with Incorporated Perovskite-Structured Nanofiller Study: Future of Cost-effective Membrane Fabrication 21 3.1.1 Characterization of Materials 21 3.1.2 Structural Characterization of the membranes. 26 3.1.3 Chemical Characterization of the membranes. 27 3.1.4 Physiochemical Properties of the membranes. 28 3.1.5 Mechnical stability analysis 30 3.1.6 Transport phenomena of membranes 31 3.1.7 ZBFB cell performance 35 3.1.8 Post membrane analysis 42 3.1.9 Summary 47 3.2 Hydrophobic Organic Additive-Integrated SPEEK Blend Membrane Study: Scaling up for Large-Scale Battery Application 48 3.2.1 Characterization of Materials 48 3.2.2 Structural Characterization of the membranes 49 3.2.3 Chemical Characterization of the membranes 52 3.2.3 Mechanical stability analysis 53 3.2.4 Transport phenomena of membranes 55 3.2.5 Physiochemical Properties of the membranes. 60 3.2.6 ZBFB cell performance 62 3.2.7 Summary 70 IV. CONCLUSION 72 V. References 74
