Dry-processed thick electrode design with a porous conductive agent enabling 20 mA h cm−2 for high-energy-density lithium-ion batteries†

Designing thick electrodes is essential for applications of lithium-ion batteries that require high energy densities. Introducing a dry electrode process that does not require solvents during electrode fabrication has gained significant attention, enabling the production of homogeneous electrodes with significantly higher areal capacity than the conventional wet electrode process. This study reports the importance of selecting appropriate conductive agents for dry-processed electrodes and optimizing the electrode composition based on the design principles by electrode parameters. By applying various conductive agents in the dry process, we discovered that the porous spherical conductive agent improves both the electrical performance and lithium-ion transport characteristics, which are difficult to incorporate in conventional wet processes. Additionally, optimizing the content of the porous spherical conductive agents within the range of 2–3 wt% through the analysis of electrode parameters enables the fabrication of high-energy-density cathodes with areal capacities of 10–20 mA h cm⁻² and a composite density of 3.65 g cm⁻³. This dry-processed cathode outperforms graphene- or carbon nanotube-based cathodes, showing excellent rate performance (88% capacity at 1C) and outstanding cycle life (80% capacity retention at the 418th cycle).