Metal oxyhalides and halides for use as electrode materials in Li-ion batteries

Synthesis of select metal halides and oxyhalides are explored in the form of direct fluorination using a fluidized bed reactor system, direct chlorination using hydrogen chloride gas, and a degradation dehydration reaction as novel methods towards the synthesis of these select metal halides and oxyhalides. The flexibility of the direct fluorination technique is demonstrated by the ability to vary the degree of fluorination based on the reaction conditions of temperature, time, and fluorine concentration. Conversion electrodes in the form of metal halides and metal oxyhalides are investigated as both anode and cathode materials for lithium ion batteries. The resulting electrochemical properties of the materials are reported. In the case of titanium oxydifluoride it is shown how the precursor material can alter the properties of the final product. Alpha ruthenium (III) chloride is demonstrated to be an excellent compound for the study of metal chlorides in lithium ion batteries as it shows a high reversible capacity over many cycles. Reversible cycling data for iron (III) oxychloride is shown using both standard organic and ionic liquid electrolytes. This demonstrates the importance of using the proper electrolyte with a specific active material to achieve the optimal properties from the battery system. Collectively what is shown is the viability of conversion type metal halide and oxyhalide electrodes to be used in lithium ion batteries.