Synthesis of LiMnO2-graphene nanoplatelets composite by hydrothermal process

Abstract

The pristine o-LiMnO₂ (PL) and in-situ composite samples between o-LiMnO₂ and graphene nanoplatelets (GNPs) (L-xGNP with x = 1, 3, 5, 7, 9 wt.% of GNPs) were synthesized successfully via a one-step hydrothermal process. The characterization and electrochemical measurement of the obtained samples were performed. The introduction of GNPs in the L-xGNP composites reduces the growth of primary particles of o-LiMnO₂ and provides improved performances as cathode in lithium-ion batteries compared to the PL sample, in which the L-3GNP (3 wt.% GNPs) is the optimal sample amongst the L-xGNP composites with the highest discharge capacities of 151.90 mAhg^-1 at 0.1 C and 98.46 mAhg^-1 at 1 C and remained over 94 % of the discharge capacity after 90 cycles. It also exhibited the lowest charge-transfer resistance (72.007 Ω) and the highest electrical conductivity (4.95 × 10⁻⁵ S·cm⁻¹). The enhanced performance is attributed to improved Li⁺ storage capability, reduced electrode volume variation, and suppressed Mn³⁺ dissolution.