(Invited) Design and Development of Novel Electrolytes for Batteries and Supercapacitors

Abstract

Electrolytes are often forgotten parts of batteries and super capacitors compared to numerous review papers and textbooks describing properties of electrode materials. The intention of the present work is to fill the gap and bring electrolytes to the attention of the scientists working in the field of electrochemical energy conversion and storage devices. New challenges appearing on the nowadays battery and super caps market force researchers to design novel electrolytes often baring features not found in up to date studied systems. These challenges are aimed to be addresses and discussed. In the present work three types of electrolytes for application in modern batteries or super caps will be presented and discussed.Strategy on design of new Huckel type anions for electrolyte salts is presented in the context given by the review of legacy and state-of-the-art systems. Synthesis, conditions for handling, stability and electrochemical parameters of salts used or with a potential for use in lithium-ion cells are described. Effect of solvent mixtures, selection strategy of salts and solvents for battery mixtures for maximization of chosen parameters or for given application is explained.We are going to show how crystallographic studies allow for a better understanding of electrochemical properties of Huckel type salts. Comprehensive structure analysis of crystalline materials reveals valuable information about coordination ability of anions and provides the basis to develop the model of poly (ethylene oxide) electrolytes and liquid systems. Results revealing new aggregation modes at high concentrations of lithium salts involving releasing cations by self-assembly of anionic sub network will be presented.The discovering and understanding the phenomena related to the organization of such systems in the solid state is crucial for the elaboration of novel electrolytes and gives information about cation and anion coordination in electrolytes.Also we are going to present novel hybrid polymeric electrolytes with unmodified and surface modified fillers based on silica, alumina and titania of different grain size. Special emphasize will be put on proper choice of the filler leading to preparation of composite system with enhance conductivities and lithium cation transference number compared to unmodified polymeric electrolytes.At the end we are going to discuss properties of several proton conducting gel polymeric electrolytes with various solvent ratios, to be used as electrolytes in super capacitor applications. The influence of the gel composition on the ionic conductivity, temperature behavior and electrochemical properties has been studied in a large temperature range (-40 to 80 °C)..