Lithiophilic Zn₃N₂-Modified Cu Current Collectors by a Novel FCVA Technology for Stable Anode-Free Lithium Metal Batteries

Abstract

Anode-free lithium metal batteries (AFLMBs) offer high-energy-density battery systems, but their commercial viability is hindered by irregular lithium dendrite growth and “dead Li” formation caused by current collector defects. This study employed filtered cathode vacuum arc (FCVA) technology to fabricate Cu current collectors (CCs) with a lithiophilic Zn3N2 film. This advanced preparation process ensures an evenly distributed film that reduces the nucleation overpotential, homogenizes the interfacial electric field during plating/stripping processes, inhibits lithium dendrite growth, and forms a stable solid-electrolyte interphase (SEI). Our results show that the advanced Zn3N2@Cu CCs exhibit superior performance with a high CE of above 99.3% after 230 cycles at a current density of 0.5 mA cm–2 and an area capacity of 1 mAh cm–2. Additionally, Li–Zn3N2@Cu||Li–Zn3N2@Cu symmetrical cells had a longer stable cycle time of over 1000 h than that of Li||Li and Li–Cu||Li–Cu symmetrical cells at a current density of 1 mA cm–2 and an area capacity of 2 mAh cm–2. Compared with bare Cu CCs, the capacity retention rate is increased from 14.9 to 63.1% after 100 cycles with a 0.5C rate in the AFLMBs with LFP as the cathode. This work provides a pioneering, eco-friendly, and effective solution for the fabrication of anode CCs in AFLMBs, addressing a significant challenge in their commercial application.

Anode-free lithium metal batteries: a promising flexible energy storage system

“…A critical examination of Zhu's modification of a copper current collector with a zinc nitride (Zn 3 N 2 ) film highlights the feasibility of application for these metallic compounds. 83 The relatively low nucleation overpotential on Zn 3 N 2 @Cu shown in Fig. 10d and e demonstrates the lithiophilic properties of the fabricated layer, thus stabilizing the Li nucleation process on the modified CC.…”

“…Moreover, the exploration of alternative materials such as zinc and titanium and three-dimensional current collectors is opening up new paths for performance benefits and potential cost reductions. 83 This transition is expected to bolster the overall stability of AFLMBs, marking a significant stride towards batteries that can reliably power the future. 94,97…”

Influence of the PET–PTFE Separator Pore Structure on the Performance of Lithium Metal Batteries

“…Liao et al. reported a filtered cathode vacuum arc to the lithiophilic Zn 3 N 2 film on Cu current collectors, homogenizing the interfacial electric field during plating/stripping processes . Li’s group proposed a separator modification strategy for blocking dendritic deposition via dendritic channels, which can diversify the growth directions of lithium and contribute to a more substantial homogenizing process of lithium ions .…”