Near-strain-free anode architecture enabled by interfacial diffusion creep for initial-anode-free quasi-solid-state batteries

Anode-free (or lithium-metal-free) batteries with garnet-type solid-state electrolytes are considered a promising path in the development of safe and high-energy-density batteries. However, their practical implementation has been hindered by the internal strain that arises from the repeated plating and stripping of lithium metal at the interlayer between the solid electrolyte and negative electrode. Herein, we utilize the titanium nitrate nanotube architecture and a silver-carbon interlayer to mitigate the anisotropic stress caused by the recurring formation of lithium deposition layers during the cycling process. The mixed ionic-electronic conducting nature of the titanium nitrate nanotubes effectively accommodates the entry of reduced Li into its free volume space via interfacial diffusion creep, achieving near-strain-free operation with nearly tenfold volume suppressing capability compared to a conventional Cu anode counterpart during the lithiation process. Notably, the fabricated Li 6.4 La 3 Zr 1.7 Ta 0.3 O 12 (LLZTO)-based initial-anode-free quasi-solid-state battery full cell, coupled with an ionic liquid catholyte infused high voltage LiNi 0.33 Co 0.33 Mn 0.33 O 2 -based cathode with an areal capacity of 3.2 mA cm −2 , exhibits remarkable room temperature (25 °C) cyclability of over 600 cycles at 1 mA cm −2 with an average coulombic efficiency of 99.8%. Initially anode-free batteries with garnet-type solid-state electrolytes suffer from internal strain by repeated Li plating/stripping. Here, the authors propose a near-strain-free anode architecture for interfacial diffusion of Li metal that suppresses volume expansion during cycling.