Energy storage devices and components thereof

A method of preparing an electrode precursor composition for use in an alkali metal ion secondary cell comprises forming a first mixture from one or more electrolyte components, a gelling polymer, and carbon nanotubes, and mixing the first mixture with an electrochemically active material to thereby form an electrode precursor composition comprising a polymer-electrolyte gel matrix phase and a dispersed phase comprising electrochemically active material and carbon nanotubes. The electrolyte component preferably comprises an alkali metal salt such as LiBF4, LiTFSI, LiFSI or LiTDI and an organic solvent. The carbon nanotubes may comprise single wall (SWCNT) and/or multi-wall carbon nanotubes (MWCNT). The carbon nanotubes may be dispersed in the polymer-electrolyte gel matrix using sonication, ultrasonication and/or rotor-stator homogenisation. The gelling polymer may comprise one or more of PVDF, HFP, PVDF-HFP, PMMA, PAN and/or PEO. Also disclosed are an electrode precursor composition and an electrode for an alkali metal ion secondary cell obtained or obtainable by the method, an electrochemical secondary cell comprising the electrode, and an electrochemical energy storage device comprising the electrochemical secondary cell.