Preparation of High Performance Polyethylene Oxide (PEO) Based Solid Polymer Electrolyte for Lithium Ion Battery
DescriptionLithium batteries (usingsolid electrolytes) have high potential as power sources for the current energy economy. Although they are satisfactory in portable electronic applications, their usage in more demanding applications, such as in automobiles, are still far from satisfactory. There are certaininherent problems that have been indentified in all solid polymer electrolytes (SPE)for their full implementation into lithium ion batteries, such as: (1) low ion conductivity and low (tensile) mechanical properties; (2) low Li+ion transport number; and (3) weak solid-solid interface between the solid polymer electrolyte (SPE) films and the electrodes. For common polymer based (such as polyethylene oxide (PEO) base) polymer electrolytes, the main challenge lies in the requirement for both high ion conductivity and good mechanical properties. Sincehigh ion conductivity requires the polymer (such as PEO) chains to be flexible and remained to be amorphous, which will result in the SPE films to possess low mechanical properties.In order to solve this problem,we propose in this projectthata comb like copolymer with cross-linked polymer main chainandshort flexible polymer (such as polyethylene glycol (PEG)) side chainis to be developed. The cross-linked polymer main chain will impart the SPE film with good mechanical properties, while the flexible side chains will provide the high ion conductivity. In addition, Lewis acids will be incorporated into the SPE with the aim to)increase the Li+ion transport number. In order to enhance the interactions between the SPE films to be developed as described above with the electrodes surfaces,we also proposethe decorating of the SPE film surfaces with nanoparticles corresponding with electrode materials that the SPE film will be in contact with, respectively. This decoration of SPE film surfaces will be executed by ultrasonication, which we have developed recently in our laboratory.Finally, the effect of Li salt concentration, PEG chain length and density, Lewis acid content, and ultasonication conditions on the ion conductivity and cyclic life of the polymer electrolyte and Li ion battery will be fully investigated in this project.
|Effective start/end date||1/12/13 → 30/05/18|