Effectively Regulating More Robust Amorphous Li Clusters for Ultrastable Dendrite‐Free Cycling

Abstract

A disordered phase in Li-deposit nanostructure is greatly attractive, but plagued by the uncontrollable and unstable growth, and the nanoscale characterization in the structure. Here, fully characterized in cryogenic transmission electron microscopy (cryo-TEM), more robust amorphous-Li (ALi) clusters are revealed and effectively regulated on heteroatom-activating electronegative sites and an advanced solid electrolyte interphase (SEI) layer. Heteroatom-activating electronegative sites capably enhance the electrostatic interaction of Li + and heteroatom-doping graphene-like film (HDGs), meaning lower Li diffusion barrier and larger binding energy that is confirmed by small nucleation overpotentials of 13.9 and 10 mV at 0.1 mA cm −2 in the fluoroethylene carbonate-adding ester-based (FEC-ester) and LiNO 3 -adding ether-based (LiNO 3 -ether) electrolytes. Orderly multilayer SEI structure comprised of inorganic-rich components enables fast ion transports and durable capabilities to construct highly reversible and long-term plating/stripping cycling. ALi cluster anodes exhibit non-crystalline morphologies and perform ultrastable dendrite-free cycling over 2800 times. Stable ALi clusters are also grown in LiFePO 4 (LFP) (LFP-ALi-HDGs-N||LiFePO 4 [LFP]) full cells with advantageous capacities up to 165.5 and 164.3 mAh g −1 in these optimized electrolytes at 0.1 C; the remarkable capacity retentions maintain to 93% and 91% after 150 cycles at 0.2 C. Structure viability, electrochemical reversibility, and excellent performance in ALi clusters are effectively regulated.

High Li+ coordinated solvation sheaths enable high‐quality Li metal anode

“…A 0.24 nm spacing distance in the lattice fringes is assigned to the Li (110) lattice plane. Meanwhile, crystalline diffraction spot in FFT image is also consistent with the appearance of crystalline Li in Li (110) lattice plane 54,55 . In this localized high‐concentration electrolyte of cluster‐like solvation sheaths, the Li deposit perfectly exhibits an ordered growth structure and a stable well‐proportioned spherical shape.…”

Heteroatomic interface engineering of an octahedron VSe2–ZrO2/C/MXene composite derived from a MXene-MOF hybrid as a superior-performance anode for lithium-ion batteries

“…84 The Li-cluster in porous carbon material can also provide extra ultra-high capacity. 85,86 The increasing capacity of the anode does not cause a capacity decay of the battery. However, we suggest that the increased capacity of the composite can couple with some capacity attenuation anode materials, including Si, Sn, Sb, and Bi, to achieve capacity complementarity.…”

“…It may also help the accommodation of Li cluster for storage to provide extra ultra-high capacity. 85,86 As shown in Fig. S15, † without the participation of ZrO 2 and porous carbon, VSe 2 /MXene suffers during the repeated cycles, which leads to degenerative performance.…”

Cryo-EM for battery materials and interfaces: Workflow, achievements, and perspectives

“…Amorphous-rich Li is proved beneficial to reduce the dendritic growth and enhance electrochemical reversibility. Besides tuning current density and electrolyte ( Wang et al., 2020b ), amorphous Li clusters can be obtained by introducing heteroatom-activating electronegative sites on the current collector and thus improving the cycling performance ( Huang et al., 2021 ). Although these works enrich the understanding of the Li growth, much work is still needed to uncover the behaviors of Li metal at different conditions, such as varied electrolytes, temperature, and pressures.…”