Ultrahigh mass loading, binder-free synthetic approach for mesoporous graphitic carbon in 3D current collector for high energy lithium-ion batteries

Abstract

To achieve high-energy lithium-ion batteries (LIBs), both a high mass loading of electrode material onto the current collector and a binder-free process are simultaneously needed, but this remains a challenge. In this study, a novel method is introduced for the binder-free high mass loading of mesoporous graphitic carbon (m-G) onto a 3D current collector. Specifically, polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) is used as both the carbon source and the template for the mesoporous structure. The m-G is successfully synthesized on 3D copper foam (3D Cu) without using a binder by first loading the PS-b-P2VP onto the 3D Cu and subsequently converting it into m-G. Furthermore, in contrast to the delamination-prone traditional slurry coating method, an ultra-high areal mass loading (32 mg cm⁻²) of m-G is achieved without any delamination from the 3D Cu by simply increasing the feeding amount of PS-b-P2VP. When half-cell LIBs were fabricated using the obtained electrode as the anode, an outstanding energy storage performance was achieved, including a high areal capacity of 5.5 mA h cm⁻² at a current density of 3.5 mA cm⁻², an excellent rate capability, and good cycle stability (>500 cycles).