Characterisation and Modelling of Potassium-Ion Batteries
Potassium-ion batteries (KIBs) are emerging as a promising alternative technology to lithium-ion batteries (KIBs) due to their significantly reduced dependency on critical minerals. KIBs may also present an opportunity for superior fast-charging compared to LIBs, with significantly faster K-ion electrolyte transport properties already demonstrated.
In the absence of a viable K-ion electrolyte, a full-cell KIB rate model in commercial cell formats is required to determine the fast-charging potential for KIBs. A thorough and accurate characterisation of the critical electrode materials properties determining rate performance - the solid state diffusivity and exchange current density - has not yet been conducted for the leading KIB electrode materials.
In the paper 'Characterisation and modelling of potassium-ion batteries' (published in Nature Communications), the authors accurately characterise the effective solid state diffusivities and exchange current densities of the graphite negative electrode and potassium manganese hexacyanoferrate K2Mn[Fe(CN)6](KMF) positive electrode, through a combination of optimised material design and state-of-the-art analysis. They also present a Doyle-Fuller-Newman model of a KIB full cell with realistic geometry and loadings, identifying the critical materials properties that limit their rate capability.
