Multiscale interfacial stabilization via prelithiation separator engineering for Ah-level anode-free lithium batteries.

Shao, Ahu; Wang, Helin; Zhang, Min; Liu, Jiacheng; Cheng, Lu; Li, Yunsong; Guo, Yuxiang; Wang, Zhiqiao et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Anode-free lithium batteries represent a promising avenue for high-energy-density storage, yet their practical application is hindered by lithium inventory loss from parasitic interfacial reactions, cathode degradation, and limited Li<sup>+</sup> reversibility. Herein, we propose a polyolefin separator integrated with a Li<sub>2</sub>S@C sacrificial layer, achieving multiscale interfacial stabilization in Ah-class anode-free pouch cells. This approach simultaneously replenishes the customized Li<sup>+</sup> inventory during the formation cycle and establishes the lithium polysulfide-containing cathode interface with high-voltage tolerance (till 4.5 V). Real-time tracking via in-situ electrochemical impedance spectroscopy and transmission-mode operando X-ray diffraction reveals accelerated Li<sup>+</sup> diffusion kinetics and stabilized phase evolution in LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> cathode interfaced with Li<sub>2</sub>S@C|PE prelithiation separator. Consequently, a 1.22 Ah pouch cell with an Ag-modified Cu foil and LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> cathode is assembled with Li<sub>2</sub>S@C|PE separator and exhibits gravimetric and volumetric energy densities of 450 Wh kg<sup>-1</sup> and 1355 Wh L<sup>-1</sup>, respectively. This prelithiation protocol demonstrates upscaling potential and generic applicability to secure the interfacial chemistries for anode free/less lithium metal batteries.