THE ORTHO-PHOSPHATE ARROJADITE AS A NEW MATERIAL FOR CATHODES IN LI-ION BATTERIES

摘要

Li-ion batteries as power storage devices for many technical applications have developed tremendously during the last 15 years. Upon analyzing commercially available Li-ion batteries based on different cathode materials, it becomes clear that the durability and the failure of the battery as a whole is closely connected to the most commonly used assembly of the cathode which consists of a redox active material (cathode material), graphite and organic binder. Strain and stress in the cathode material during the cycle process caused by the variable lithium content are the main reasons for these problems.A novel cathode material based on a transition metal-rich ortho-phosphate is presented utilizing the same chemistry with a different structure. It exhibits an excellent cycle behavior because its lithium content affects its structure negligibly.. In contrast to the commercially used LiFePOt cathode material in 3.5V batteries this novel ortho-phosphate material offers the opportunity to be used in the so-called "5V-technology". This is possible without the use of expensive and polluting transition metals such as cobalt or nickel.