Recent Advances in Scalable, High-Mass Loaded Electrodes for Grid-Scale Energy Storage

The increasing electrification of daily life as well as the intermittent characteristic of renewable energy sources require viable solutions for grid-scale energy storage. Critical considerations for grid storage applications are electrode mass loading and electrode thickness as these features govern battery pack energy density, an important factor in determining manufacturing costs. For this reason, there is increased interest in finding new ways of creating electrodes with high mass loading. In this review, various high-mass loading fabrication approaches are considered for positive electrode materials used in batteries. The benchmark used for high mass loading is above 20 mg cm^-2, which is higher than the practical limit of conventional tape-cast electrodes. Several different electrode approaches are described including templating, laser patterning, direct ink writing, and electrodeposition. A variety of materials are covered with the most prominent being LiFe(PO₄) (LFP), LiCoO₂(LCO), and MnO₂. In research to date, scalable electrochemical performance has been achieved with mass loadings over 100 mg cm^-2. Areal capacities as high as 14.7 mAh cm^-2 at 1.82 mA cm^-2 have been achieved in non-aqueous electrolytes and 9.8 mAh cm^-2 at 10 mA cm^-2 in aqueous electrolytes. These results establish that the mass loading of electrodes can be scaled up without compromising their electrochemical properties.