Graphene collage on Ni-rich layered oxide cathodes for advanced lithium-ion batteries.

Park, Chang Won; Lee, Jung-Hun; Seo, Jae Kwon; Jo, Won Young; Whang, Dongmok; Hwang, Soo Min; Kim, Young-Jun · Nat Commun · 2021

basic_science · Level V

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Abstract

The energy storage performance of lithium-ion batteries (LIBs) depends on the electrode capacity and electrode/cell design parameters, which have previously been addressed separately, leading to a failure in practical implementation. Here, we show how conformal graphene (Gr) coating on Ni-rich oxides enables the fabrication of highly packed cathodes containing a high content of active material (~99 wt%) without conventional conducting agents. With 99 wt% LiNi<sub>0.8</sub>Co<sub>0.15</sub>Al<sub>0.05</sub>O<sub>2</sub> (NCA) and electrode density of ~4.3 g cm<sup>-3</sup>, the Gr-coated NCA cathode delivers a high areal capacity, ~5.4 mAh cm<sup>-2</sup> (~38% increase) and high volumetric capacity, ~863 mAh cm<sup>-3</sup> (~34% increase) at a current rate of 0.2 C (~1.1 mA cm<sup>-2</sup>); this surpasses the bare electrode approaching a commercial level of electrode setting (96 wt% NCA; ~3.3 g cm<sup>-3</sup>). Our findings offer a combinatorial avenue for materials engineering and electrode design toward advanced LIB cathodes.