Lithiation dynamics in vertically aligned 1T-PtSe2 and its application in dendrite-free lithium metal batteries

Abstract

Lithium metal anodes are highly promising for next-generation high-energy-density batteries due to their ultrahigh theoretical capacity and low electrochemical potential. However, their practical application is hindered by issues such as lithium dendrite growth and poor cyclability. Herein, a vertically aligned 1T-PtSe2 film on carbon cloth (PtSe2-CC) is designed to promote uniform Li plating via an in situ-formed Li2Pt/Li2Se interphase. Indeed, in situ transmission electron microscopy studies and ab initio molecular dynamics simulations elucidate the electrochemical reaction mechanism between PtSe2 nanostructures and Li metal, revealing the formation of Li2Pt and Li2Se phases that serve as effective nucleation sites for lithium. These sites facilitate a homogeneous Li+ flux, thereby significantly enhancing electrochemical performance. The PtSe2-CC electrode achieves ultralow nucleation overpotential (11.0 mV at 5 mA cm−2), stable cycling lifetime (>400 h at 5 mA cm−2, 5 mAh cm−2), and a high Coulombic efficiency (99.7% over 200 cycles), offering a promising strategy for dendrite-free Li metal batteries.