Durable Li₂CN₂ Solid Electrolyte Interphase Wired by Carbon Nanodomains via In Situ Interface Lithiation to Enable Long‐Cycling Li Metal Batteries

Abstract

Lithium metal batteries (LMBs) are becoming the promising candidate of highenergy storage systems. However, the fragile natural solid electrolyte interphase (SEI) cannot retard the Li dendrite growth at anode, which will cause the low coulombic efficiency (CE) of Li plating/stripping and safety hazards in LMBs. Here, an in situ construction strategy of novel artificial SEI consisting of Li 2 CN 2 ionic conductor wired by carbon nanodomains via dicyandiamide solution reaction method on Li metal surface is proposed. This lithiophilic Li 2 CN 2 has the higher anti-reduction stability and longer critical length for Li dendrite, showing the excellent dendrite suppressing ability. The wired carbon domains promote the electron connection and charge homogenization in SEI, leading to the uniform Li nucleation around Li 2 CN 2 /C grains with enhanced interface kinetics and reduced polarization. This dual conductive Li 2 CN 2 /C network enables the durable preservation of high CE and low voltage hysteresis during Li plating/stripping, endowing LiNi 0.8 Mn 0.1 Co 0.1 O 2 /Li cells with ultralong cycling life exceeding 1000 cycles at high rate. The cycling stabilization effect is also remarkable even under thin Li anode and high-loading cathode conditions. This study provides a solution to robust SEI configuration of high conductivity via in situ interface lithiation reaction for high-performance LMBs.

Triazine-Based Graphitic Carbon Nitride Thin Film as a Homogeneous Interphase for Lithium Storage

“…At first, an activation process was performed at a constant current density of 0.1 mA cm –2 (Figure S16a). The presence of abundant N-containing structures provides Lewis-base-like sites that can give rise to well-distributed Li–N interactions upon initial lithiation. − The EIS results reveal that the lithiated lithiates have a t-CN reduced interfacial impedance with respect to the native SEI on the bare Cu current collector (Figure S16b). According to the results of the galvanostatic intermittent titration technique (GITT), the activated t-CN layer possesses a high chemical Li + diffusion coefficient ( D Li + ) of 10 –12 ∼10 –10 cm 2 s –1 at different states-of-charge (SOCs) during activation (Figure S17).…”

Suppressing Li dendrite by a guar gum natural polymer film for high‐performance lithium metal anodes

“…Because of the high affinity between lithium ions and oxygen-containing functional groups. In addition to hydroxyl (AOH), 37 nitrile (ACN), 40 and polar fluorocarbon (ACF) 41 can also have the same effect. In general, the advantages of polar groups can be summarized as follows: (a) The interaction between polar groups and Li + promoted the orderly layer-by-layer deposition of Li + and inhibited the growth of Li dendrites.…”

Electrochemical Activation of Ordered Mesoporous Solid Electrolyte Interphases to Enable Ultra‐Stable Lithium Metal Batteries

“…the standard hydrogen electrode) is the most promising anode material for next-generation lithium secondary batteries. [1][2][3] However, some fatal flaws of Li metal cannot be ignored, especially the uneven Li deposition during cycling, which would cause serious dendrite growth and volume change for this hostless anode, resulting in short-circuit risk and safety issues. [4] Specifically, the metallic Li can spontaneously react with most organic electrolytes with the instant formation of a solid electrolyte interface (SEI) layer on the surface of the Li anode.…”