Boosting rate capability and cycling stability of lithium-ion batteries with high-mass-loading electrodes via printable graphene on separators

While high-mass-loading electrodes are desirable for achieving high energy density of lithium-ion batteries, their large thickness restricts charge transport, compromising electrochemical performance. Here, we introduce stencil-printable graphene on separators for lithium-ion batteries with high-mass-loading electrodes. Graphene nanoflake inks are formulated with shear-thinning properties, allowing stencil printing of uniformly deposited graphene layers with defined shapes onto separators. When used in battery assembly, the printed graphene (PG) facilitates efficient electron transport in adjoining electrodes, promoting electrochemical reaction kinetics and homogeneity. LiFePO₄ (LFP)|Li cells with PG exhibit significantly improved rate performance when compared to those without PG, delivering a specific capacity of 126 mAh g⁻¹ at a rate of 2C with an industrially relevant active material (LFP) loading of 15 mg cm⁻² and a high active material mass ratio of 95 %. Furthermore, PG reinforces cycling stability, offering a robust strategy to advance the electrochemical performance of lithium-ion batteries with high-mass-loading electrodes.