Ultrahigh concentration, single-layer of graphene paste as conductive additive for lithium-ion battery

Abstract

Graphene is a superior active material in energy storages due to its exceptional properties, such as high specific area, high electrical conductivity, and excellent chemical stability. Currently, the large-scale preparation of graphene powder constitutes a research hotspot. Usually, the as-prepared graphene powders was used directly leading to poor dispersion which greatly affects the electrode's properties. Thus, one crucial application problem which needs to be solved urgently is how to obtain ultrahigh concentration and stable dispersion of single-layer graphene. Therefore, in this work, we prepared successfully a single-layer reduced graphene oxide (RGO) powder by expansion-oxidation-expansion process. The RGO paste was obtained through high-speed ball-milling technology, offering ultrahigh concentration (27 mg/mL) and high stability. Meanwhile, the above-mentioned paste be combined with LiFePO4 (LFP) towards obtaining cathode materials for Li-ion batteries. LFP@RGO demonstrated an excellent discharge capacity of 168.3 mA h g−1 at 0.1 C, and maintained 99.9% of capacity after 100 cycles at 0.5 C. Herein, we demonstrated an effective way to prepare the ultrahigh concentration, and stable dispersion of single-layer graphene paste in the field of energy storage and conversion.