It was noted that upon heating these cubic spinels, oxygen volatilization occurred. It is most likely that these joins are, in fact, three sections through a solid solution area. (iii)Ě previously unreported join between Li2CoMn3O8 and Co1.7Mn1.3O4.

(ii)Ě previously unreported join between LiCoMnO4 and Co3O4. (i) The reported cubic spinel solid solution between LiMn2O4 and LiCoMnO4. The ternary Li2O-CoOx-MnOy phase diagram has also been studied (Chapter 5), with particular attention paid to three solid solutions: Li metal, while also replacing most of the expensive and toxic Co with Mn. The best performance found was for Co0.4Mn2.6O4, which showed good capacity retention, better specific capacity than the graphite anode materials currently used, and the lowest potential vs. On first discharge, the spinel was fully reduced to a discrete mixture of Co and Mn metal particles these could be re-oxidised to CoO and MnO on subsequent charging. These phases were studied using GCPL (Chapter 4) for possible application as anodes in Liion batteries, and were found to be able to reversibly accept Li by a reductionlreoxidation process. It was found that single phase samples with the spinel structure (with either cubic (0.00≤x:≤1.30) or tetragonal (for 1.30 < x≤3.00) symmetry could be isolated. The pseudo-binary join between cobalt oxide and manganese oxide has been studied (Chapter 3) the phase diagram has been established from room temperature to - 1400 0c. Property characterisation has been conducted using a variety of techniques (Chapter 2): thermal analysis has been carried out using thermogravimetry (TG), differential thermal analysis (DT A) and differential scanning calorimetry (DSC), electrical measurements have been made using ac impedance, battery testing has been carried out using galvanostatic cycling with potential limitation (GCPL). Samples have been studied by X-ray powder diffraction.

A number of compositions from the Li2O-CoOx-MnOy ternary phase diagram have been studied.

Anode vs cathode battery