Ordered Lithium-Ion Conductive Interphase with Gradient Desolvation Effects for Fast-Charging Lithium Metal Batteries

Abstract

Efficient desolvation and fast lithium ion (Li + ) transport are key factors for fast-charging Li metal batteries (LMBs). Here, we report a self-assembled interphase (SAI) with ordered Li + transport pathways to enable high Li + conductivity and fast Li + desolvation for fastcharging LMBs. A self-assembled structure originating from the intermolecular π−π stacking endows SAI with ordered Li + transport pathways. The regular molecular stacking and a gradient distribution of functional groups of SAI contribute to a spatially confined gradient desolvation of Li + . Thereby, a stable Li metal anode (LMA) with durable solid-electrolyte interphase, accelerated Li + transfer, and homogeneous Li plating/stripping is achieved at high rates. A full-cell battery of SAI protected LMA|LiNi 0.8 Co 0.1 Mn 0.1 O 2 delivers a high capacity of 147 mAh g −1 with an improved capacity retention for 500 cycles at 3 C (1 C = 210 mA g −1 ), and the full cell can deliver over 71% of its capacity in 12 min.

Self-Standing Single-Ion Borate Salt-Based Polymer Electrolyte for Lithium Metal Batteries

“…ToF-SIMS measurement is also carried out to probe the components of SEI; it can be seen from Figure d and e that B–O species are obviously observed on the lithium anode recovered from the PLDPB-based cell, which further indicates that the decomposition of PLDPB contributes to the SEI formation. , The B–O species is richer in the inner layer of the SEI, as demonstrated by the B 1s spectra. It is reported that the benzene-based organic moiety with planar backbone conformation and π–π interaction might be beneficial for the formation of flat and compact SEI layers and simultaneously improve the toughness and strength of SEI and thus suppress growth of lithium dendrites. ,, More importantly, a close inspection of C 1s and O 1s signals in Figure c reveals that the peaks of organic species, especially the O–C(O)–O peak, drop sharply after 200 s of sputtering, which demonstrates that the formed inner SEI might inhibit the parasitic reactions, and many fewer organic carbonate plasticizers (i.e., EC/DEC solvents) decompose in the inner part of SEI in the PLDPB-based electrolyte. On the contrary, for the LiTFSI-based cell, the O–C(O)–O peak remains almost the same without obvious attenuation during the whole XPS sputtering (see the O 1s spectra in Figure S13), indicating organic compounds might be enriched from the outer to the inner layer due to the continuous consumption and decomposition of plasticizers .…”

Bipolar Polymeric Protective Layer for Dendrite‐Free and Corrosion‐Resistant Lithium Metal Anode in Ethylene Carbonate Electrolyte

“…It is evident that the PVA-CN polymer effectively enhances the stability of the electrode-electrolyte interface and restrains uncontrolled growth of Li dendritic, which is attributed to the abundance of À OH groups in the the PVA-CN polymer. [27,28] To further understand the underlying mechanism of how the PVA-CN in BPPL stabilizes Li with electrolyte, we investigated the desolvation process of solvated Li + , as reported in the previous study. [7] It's widely acknowledged that the C=O group of EC binds to Li + , and the typical solvation number for the first solvation shell is n = 4, denoted as Li(EC) 4…”

“…In contrast, Li deposition within PVA‐CN+LE demonstrated a dendrite‐free and denser layer even after 16 mins at 5 mA cm −2 (Figure 3b). It is evident that the PVA‐CN polymer effectively enhances the stability of the electrode‐electrolyte interface and restrains uncontrolled growth of Li dendritic, which is attributed to the abundance of −OH groups in the the PVA‐CN polymer [27,28] …”

Unveiling Confinement Engineering for Achieving High‐Performance Rechargeable Batteries

“…[ 39 ] The confinement effect holds the promise of facilitating the decomposition of solvated metal ions by directly regulating the physical and chemical properties of the electrolyte, ultimately inhibiting side reactions. [ 40 ] Compared to the concentrated electrolyte, the confinement effect effectively reduces the reactivity of free solvent molecules and induces desolvation by directly modulating the chemical environment of the liquid electrolyte. This approach enables the production of electrolytes with enhanced electrochemical performance while maintaining the same salt concentration, making it a promising alternative modification for liquid electrolytes.…”