# Expediting Lithium Electrochemistry via a Bilayer for High-Rate Lithium Metal Batteries

## TL;DR

A bilayer design for lithium metal batteries improves electrochemical stability and enables high-rate performance by preventing dendrite growth and ensuring smooth lithium deposition.

## Contribution

The novel bilayer artificial solid-electrolyte interphase (ASEI) enables three-dimensional lithium plating and suppresses dendrite formation at high current densities.

## Key findings

- The BL–Li anode achieves a low overpotential of ≈120 mV at 20 mA cm⁻² and 10 mAh cm⁻².
- The bilayer design sustains smooth Li deposition and stripping for over 300 h under high-rate cycling.
- The ASEI-enabled electrode demonstrates outstanding rate capability and long-term cyclability in full Li metal battery cells.

## Abstract

The bilayer combines an electron‐conductive framework and an ion‐conductive layer that facilitates Li⁺ transport, effectively separating charge pathways for enhanced electrochemical stability.Porous fibers with uniformly dispersed Ag nanoparticles provide nucleation sites for uniform Li plating and a 3D network that suppresses dendrite growth.The BL–Li anode shows a low overpotential of ≈120 mV at 20 mA cm⁻² and 10 mAh cm⁻², sustaining smooth Li deposition and stripping for over 300 h under high‐rate cycling.

The bilayer combines an electron‐conductive framework and an ion‐conductive layer that facilitates Li⁺ transport, effectively separating charge pathways for enhanced electrochemical stability.

Porous fibers with uniformly dispersed Ag nanoparticles provide nucleation sites for uniform Li plating and a 3D network that suppresses dendrite growth.

The BL–Li anode shows a low overpotential of ≈120 mV at 20 mA cm⁻² and 10 mAh cm⁻², sustaining smooth Li deposition and stripping for over 300 h under high‐rate cycling.

The online version contains supplementary material available at 10.1007/s40820-026-02146-3.

The intrinsic characteristics of the Li metal anode, particularly its ultra-high specific capacity (3860 mAh g−1) and low redox potential (−3.04 V vs. SHE), theoretically make it ideal for high-rate charge/discharge operations. However, the high Li self-diffusion barrier causes uncontrolled plating/stripping dynamics and severe volume fluctuations, hindering stable performance at elevated current densities. In this study, we introduced an artificial solid-electrolyte interphase (ASEI) engineered with a bilayer that transcends conventional planar deposition, facilitating Li nucleation and growth along three-dimensional electronic percolation pathways. This spatially distributed, lateral plating morphology significantly reduced charge-transfer resistance, suppressed dendrite formation, and mitigated cell degradation under high charging currents. Consequently, the ASEI-enabled Li metal electrode maintained low overpotentials at an areal capacity of 10 mAh cm−2 and a current density of 20 mA cm−2 for over 300 h, while demonstrating outstanding rate capability and long-term cyclability in LiFePO4(LFP)‖Li and LiNi0.8Co0.1Mn0.1O2 (NCM811)‖Li full cells. By elucidating these intrinsic anode behaviors, our findings establish a fundamental design strategy for high-rate performance, potentially advancing the commercialization of Li metal batteries.

The online version contains supplementary material available at 10.1007/s40820-026-02146-3.