A Rational-Designed Interlayer for Anode-Free Lithium-Metal Batteries.

Anode-free lithium metal batteries (AFLMBs) are attracting significant attention due to their easy fabrication and high volumetric energy density. However, inhomogeneous deposition of lithium usually leads to dead Li or dendrites, in the meantime, the limited active lithium inventory also restricts the cycle life of AFLMB. In this study, a mixed ion/electron conductive interlayer (SNAF) composed of Si nanoparticles, carbon nanotubes (CNT), lithium polyacrylic acid (PAALi), and LiF is designed to stabilize the deposition process of lithium. Of which Si serves as a lipophilic site and reduces the nuclei overpotential, CNT decreases the local current density and thus enhances the high current deposition stability, while PAALi and LiF work as an artificial solid electrolyte interphase (ASEI) and reduce the irreversible active Li loss. It shows that with SNAF interlayer, the thickness of the lithium deposition is close to the theoretical value even up to 10 mAh cm, so as to the stripping process. Moreover, it also enabled the AFLMB to work even under the high current density of 4.29 mA cm. It is believed this facile interlayer strategy can greatly promote the advancement of AFLMB research.