Constructing Self‐Adapting Electrostatic Interface on Lithium Metal Anode for Stable 400 Wh kg⁻¹ Pouch Cells

Abstract

The realization of large‐capacity, high‐energy‐density Li metal battery technology is seriously impeded by dendrite growth and massive dead lithium formation upon cycling. Here, a stable flexible electrostatic self‐adapting polymer (poly(1‐benzyl‐3‐vinylimidazolium), (PBM)) interface is reported to regulate lithium‐ion deposition for dendrite‐free lithium metal batteries. The cationic PBM interlayer can adaptively tune the surface current density near the lithium/electrolyte interface, inducing a uniform distribution of current density and lithium ions and thus achieving dendrite‐free Li deposition under harsh conditions (lean electrolyte 8.75 µL mAh−1, high areal capacity >4 mAh cm−2). Moreover, the tethered phenyl groups endow PBM with a low reduction potential of −3.7 V versus standard hydrogen electrode by decreasing Hirshfeld charge at the reductive site. This avoids electrochemical reduction and therefore ensures the long‐term stability of the PBM interface. Consequently, the Li|PBM@Cu asymmetric cells deliver a high average Coulombic efficiency of 99.38% at 8 mAh cm−2 with lean electrolyte. Notably, the 5.1 Ah LiNi0.8Co0.1Mn0.1O2|PBM@Li pouch cell exhibits excellent cycling stability (0.011% decay/cycle) and high energy density (418.7 Wh kg−1) under realistic conditions (lean electrolyte 2.5 g Ah−1, high areal capacity 5.7 mAh cm−2, and high current density 2.7 mA cm−2).

Engineering a self-adaptive electric double layer on both electrodes for high-performance zinc metal batteries

“…The appearance of tertiary amine and N + in the N 1s spectrum suggests the stability of ImS on the Zn anode surface during the charge/discharge process. 64 And as the Ar + sputtering depth increases, the N 1s spectrum signal disappeared, which indicated that ImS was only adsorbed on the surface. 37 This result is consistent with the Raman spectroscopy results, and the characteristic peaks of the ImS additive did not change before and after cycling (Fig.…”

“…Meanwhile, under the effect of the electric field, the positively charged imidazole rings will aggregate at the tips of electron-rich protrusions to form a dynamic electrostatic shielding layer, which can inhibit the continuous deposition of Zn 2+ at the tips and the 2D diffusion in the self-adaptive EDL. 32,34,62–64 In addition, the other end of ImS, –SO 3 − , has a strong interaction with Zn 2+ , which can provide a new transport channel for Zn 2+ and ensure the 3D diffusion of Zn 2+ leading to an ordered and homogeneous deposition of Zn 2+ . 65–67 To further scrutinize the growth mechanism, chronoamperometry (CA) was conducted (Fig.…”

“…Meanwhile, under the effect of the electric field, the positively charged imidazole rings will aggregate at the tips of electronrich protrusions to form a dynamic electrostatic shielding layer, which can inhibit the continuous deposition of Zn 2+ at the tips and the 2D diffusion in the self-adaptive EDL. 32,34,[62][63][64] In addition, the other end of ImS, -SO 3…”

“…Compared to the ZSO electrolyte, the XPS spectra showed the characteristic peak of imidazole N + (401.6 eV), and it was shown that ImS was adsorbed on the electrode and did not decompose. 32,64 Furthermore, the N atom in ImS has lone pair electrons, which can be easily coordinated with the free H 2 O molecules to further reduce the free water content in EDL at the cathode/electrolyte interface. 80,81 Furthermore, the SEM images of the intact NVOH structure in the ImS/ ZSO electrolyte also indicate that the material is structurally stable (Fig.…”

Regulating Lithium Ion Transport by a Highly Stretchable Interface for Dendrite-Free Lithium Metal Batteries

“…Recently, numerous researchers are devoted to solving the lithium dendrite issues to enable the commercial application of LMBs. Effective strategies reported in the studies include the artificial solid–electrolyte interphase (ASEI), − Li metal hosts, − and liquid electrolyte engineering. − Among these approaches, the ASEI method has received great attention due to its tunability and effectiveness in performance improvement . Recently, the mechanical stability and chemical passivation of the ASEI have been studied extensively, which enables the ASEI to tolerate the volume change during cycling and reduce the risk of electron penetration to some extent .…”