Abstract: The invention relates to electrodes that contain active materials of the formula: AaMbXxOy wherein A is one or more alkali metals selected from lithium, sodium and potassium; M is selected from one or more transition metals and/or one or more non-transition metals and/or one or more metalloids; X comprises one or more atoms selected from niobium, antimony, tellurium, tantalum, bismuth and selenium; and further wherein 0<a?6; b is in the range: 0<b?4; x is in the range 0<x?1 and y is in the range 2?y?10. Such electrodes are useful in, for example, sodium and/or lithium ion battery applications.

Abstract: The invention relates to electrodes that contain active materials of the formula: NaaXbMcM?d(condensed polyanion)e(anion)f; where X is one or more of Na+, Li+ and K+; M is one or more transition metals; M? is one or more non-transition metals; and where a>b; c>0; d?0; e?1 and f?0. Such electrodes are useful in, for example, sodium ion battery applications.