Ag Nanoparticle-Decorated MoS2 Nanosheets for Enhancing Electrochemical Performance in Lithium Storage.

Metallic phase 1T MoS2 is a well-known potential anode for enhancing the electrochemical performance of lithium-ion batteries owing to its mechanical/chemical stability and high conductivity. However, during the lithiation/delithiation process, MoS2 nanosheets (NSs) tend to restack to form bulky structures that deteriorate the cycling performance of bare MoS2 anodes. In this study, we prepared Ag nanoparticle (NP)-decorated 1T MoS2 NSs via a liquid exfoliation method with lithium intercalation and simple reduction of AgNO3 in NaBH4. Ag NPs were uniformly distributed on the MoS2 surface with the assistance of 3-mercapto propionic acid. Ag NPs with the size of a few nanometers enhanced the conductivity of the MoS2 NS and improved the electrochemical performance of the MoS2 anode. Specifically, the anode designated as Ag3@MoS2 (prepared with AgNO3 and MoS2 in a weight ratio of 1:10) exhibited the best cycling performance and delivered a reversible specific capacity of 510 mAh·g-1 (approximately 73% of the initial capacity) after 100 cycles. Moreover, the rate performance of this sample had a remarkable recovery capacity of ~100% when the current decreased from 1 to 0.1 A·g-1. The results indicate that the Ag nanoparticle-decorated 1T MoS2 can be employed as a high-rate capacity anode in lithium-ion storage applications.