Pore-assisted lithium deposition in hierarchically porous and hollow carbon textile for highly stable lithium anode

Abstract

Lithium (Li) metal is widely accepted as the most promising anode for next-generation batteries due to its highest theoretical capacity (3,860 mA h g−1) and lowest electrochemical potential (−3.04 V versus standard hydrogen electrode). However, Li-metal anodes suffer from low Coulombic efficiency and safety issues, due to the high activity and uncontrollable Li dendrite growth. Here, we demonstrate that a novel two-stage “outside-in” Li deposition behavior achieved through the use of bio-derived hollow carbon fiber textile with unique hierarchical porosity. We show that Li deposition first occurs on the external surface because of the abundant lithiophilic pores, followed by deposition both inside and on the wall of the hollow carbon fiber. This pore-induced mechanism is crucial for the carbon fiber textile serving as a stable and robust host for uniform Li deposition. This Li composite anode exhibits a high Coulombic efficiency for more than 500 cycles and high cycling stability of over 1,400 h at a current density of 1 mA cm−2. The scalable production and the novel understanding on the function of hierarchical porous structure provide critical insights into design and synthesis of carbon-based materials as hosts for Li anodes.