Development of High Performance Lithium-Ion Plastic Batteries

Li-ion polymer batteries rank among the most promising energy storage systems which are known at the moment. They combine the high energy densities and long cycle lives, which are typical of Li-ion systems, with the advantages of the plastic configuration of polymeric systems, such as easier processing, shape flexibility, the possibility to achieve higher current and power rates, and increased safety. Aim of this project is the development of new Li-ion polymer batteries with improved performance characteristics by combining composite gel-type polymer electrolytes with new non-carbonaceous anode materials and with standard cathode materials. The gel- type polymer electrolytes were chosen due to their high conductivities, approaching those of common liquid electrolytes. A further improvement of properties such as conductivity, Li-ion transference number, and interfacial stability towards the anode and the cathode, can be achieved by adding inorganic filler materials (Si02, Ti02, ...), resulting in composite polymer electrolytes. Two types of anode materials will be tested: Li storage alloys (e.g., Sn/SnSb) with their high capacities, and Li-Ti-spinels and derivates with their excellent cycling stability. Special attention is given to the design of the composite anode and the anode/electrolyte interface and the passivation phenomena which occur there.