Lamellar-structured anodes based on lithiophilic gradient enable dendrite-free lithium metal batteries with high capacity loading and fast-charging capability

Abstract

Lithium (Li) metal batteries have attracted much attention due to extremely high energy density. However, safety concerns and limited lifetime associated with dendrite growth of Li anodes, especially at high capacity loadings and high rates, hamper their practical application. Here, we report the construction of lamellar-structured lithium host containing carbon nanotubes (CNTs), MXene nanosheets, and SnO2 nanoparticles via a simple step-by-step vacuum filtration method. The architecture is based on the lithiophilic gradient of each component, in which highly-lithiophilic SnO2 nanoparticles uniformly anchor on the lithiophilic MXene current collector, and lithiophobic CNTs act as the top protective layer. In this way, Li electrodeposition is spatially guided in a bottom-up mode free from dendrite growth. Consequently, the CNT/MXene/SnO2 scaffold accommodates a high capacity loading of 8 mAh cm−2 with only 4.6 % volume expansion. Furthermore, the Li@CNT/MXene/SnO2 electrode achieves fast-charging capability and long-term cycling stability in both symmetric cells (40 mA cm−2) and full cells (10C). This work demonstrates an efficient approach to construct dendrite-free anodes for durable and high-power lithium metal batteries.