Morphology regulation during mechanochemistry synthesis activating nanostructured aluminum lithium storage behavior.

Abstract

Aluminum (Al) is a potential anode material for lithium-ion batteries due to its high theoretical capacity and low volume expansibility. However, scalable fabrication of nanostructured Al still faces a great challenge. In addition, the lithium storage performance of Al anode materials always encounters a severe strike within a dozen discharge/charge cycles, and such an abnormal behavior of the Al anode material remains enigmatic. Herein, a mechanochemistry method without using any solvent is developed to achieve scalable production of Al nanoparticles and the morphology of the obtained Al nanoparticles could be regulated using Ketjen black (KB). KB with a chain-like structure could regulate the Al crystal growth process and the aggregation of Al nanoparticles during the solid-phase reaction, shortening the electron transfer path among Al crystals, ultimately activating the lithium storage behavior of nanostructured Al. Initial discharge/charge capacities of 630.6 and 402.0 mA h g-1 were achieved at 50 mA g-1; unfortunately, the nanostructured Al still suffered from rapid deterioration of lithium storage performance. Comprehensive analysis demonstrated that the raised energy barrier of LiAl formation and the slow lithium diffusion kinetics in the Al matrix may be the main factors destroying the lithium storage performance of the Al anode material. This work provided more evidence for illustrating the lithium storage behavior of the Al anode.