Single-Ion Conducting Polymeric Protective Interlayer for Stable Solid Lithium-Metal Batteries

Abstract

With many reported attempts on fabricating single-ion conducting polymer electrolytes, they still suffer from low ionic conductivity, narrow voltage window, and high cost. Herein, we report an unprecedented approach on improving the cationic transport number (t Li +) of the polymer electrolyte, i.e., single-ion conducting polymeric protective interlayer (SIPPI), which is designed between the conventional polymer electrolyte (PVEC) and Li-metal electrode. Satisfied ionic conductivity (1 mS cm–1, 30 °C), high t Li + (0.79), and wide-area voltage stability are realized by coupling the SIPPI with the PVEC electrolyte. Benefiting from this unique design, the Li symmetrical cell with the SIPPI shows stable cycling over 6000 h at 3 mA cm–2, and the full cell with the SIPPI exhibits stable cycling performance with a capacity retention of 86% over 1000 cycles at 1 C and 25 °C. This incorporated SIPPI on the Li anode presents an alternative strategy for enabling high-energy density, long cycling lifetime, and safe and cost-effective solid-state batteries.

Thermally Reprocessable Self-Healing Single-Ion Conducting Polymer Electrolytes

“…Despite variations in their cross-linking density, both samples displayed a relatively brittle behavior, which can be attributed to the higher portion of P­(LiSTFSI) with a high T g . Our cross-linked polymers demonstrated a tensile strength of 3 MPa, which is comparable to poly­(vinylene carbonate) . The elongation at break for our polymers ranged from 5 to 20%, similar to that of poly­(benzimidazole) electrolytes .…”

“…Our cross-linked polymers demonstrated a tensile strength of 3 MPa, which is comparable to poly(vinylene carbonate). 53 The elongation at break for our polymers ranged from 5 to 20%, similar to that of poly(benzimidazole) electrolytes. 11 Additionally, the brittleness increased with higher furan composition due to a decrease in the average chain length between cross-linking points.…”

Fiber-reinforced quasi-solid polymer electrolytes enabling stable Li-metal batteries

“…The polymer electrolyte with a high Li + transport number is beneficial for inhibiting Li dendrites and undesirable side reactions due to their potential to reduce the buildup of ion concentration gradients. [43][44][45][46][47] According to previous reports, 43,48,49 the sulfonate anions in SPSS generally display low pairing strength with Li + , which could enhance the transport of Li + , reaching higher ionic conductivity. As shown in Fig.…”

Nanoscale Ion Transport Enhances Conductivity in Solid Polymer-Ceramic Lithium Electrolytes

“…The ion transport can be quantitatively expressed by three basic transport parameters: the ion mobility, the free ion concentration, and the transference number . To tailor these parameters several electrolyte architectures have been proposed and investigated. − Among the vast structural variability of the studied electrolytes, representative electrolyte types are related to single-ion conductors, cross-linked, gel, plasticized, nanostructured block copolymers, and composite electrolytes. − Each type has significant advantages and disadvantages. For example, the single-ion polymer electrolytes possess the unique advantage of ion transference number close to unity where the anions are covalently bonded to the polymer backbone and the free ions (cations) transport through the polymer chains .…”