Lithium Metal Batteries Enabled by Interfacial-Adhesive Amphoteric Polymer Nanosheets on Separator

TY - JOUR

T1 - Lithium Metal Batteries Enabled by Interfacial-Adhesive Amphoteric Polymer Nanosheets on Separator

AU - Wang, Ke

AU - Zhao, Teng

AU - Lv, Ruixin

AU - Tang, Wangming

AU - Yu, Tianyang

AU - Li, Li

AU - Wu, Feng

AU - Chen, Renjie

N1 - Publisher Copyright: © 2026 Wiley-VCH GmbH.

PY - 2026/5/26

Y1 - 2026/5/26

N2 - Functional modification of separators represents an effective strategy for enhancing the performance of lithium metal batteries, wherein robust interfacial adhesion between the coating and the separator substrate serves as a critical prerequisite for long-term protection. Here, a functional separator coating based on amphoteric polymer nanosheets was developed. By compositing poly(p-aminodiphenylamine) sulfonate nanosheets (p-SPA NS) with a polyurethane (PU) binder and coating them onto an amine-functionalized separator, good adhesion strength was achieved through strong interfacial interactions, thereby establishing a foundation for long-term coating stability. The amphoteric structure of p-SPA facilitated anion anchoring via its –NH+ groups while synergistically promoting lithium salt dissociation and low-energy-barrier Li+ transport through its sulfonate groups, significantly enhancing ion transport kinetics. Furthermore, the conjugated structure within the coating induced the formation of an inorganic-rich SEI layer, which further improved deposition uniformity. Benefiting from this synergistic mechanism, the Li||LiFePO4 battery equipped with the p-SPA NS@PU separator demonstrated stable cycling for over 400 cycles under a high mass loading of 11.24 mg cm−2 at 3C, with a capacity retention of 91.4%.

AB - Functional modification of separators represents an effective strategy for enhancing the performance of lithium metal batteries, wherein robust interfacial adhesion between the coating and the separator substrate serves as a critical prerequisite for long-term protection. Here, a functional separator coating based on amphoteric polymer nanosheets was developed. By compositing poly(p-aminodiphenylamine) sulfonate nanosheets (p-SPA NS) with a polyurethane (PU) binder and coating them onto an amine-functionalized separator, good adhesion strength was achieved through strong interfacial interactions, thereby establishing a foundation for long-term coating stability. The amphoteric structure of p-SPA facilitated anion anchoring via its –NH+ groups while synergistically promoting lithium salt dissociation and low-energy-barrier Li+ transport through its sulfonate groups, significantly enhancing ion transport kinetics. Furthermore, the conjugated structure within the coating induced the formation of an inorganic-rich SEI layer, which further improved deposition uniformity. Benefiting from this synergistic mechanism, the Li||LiFePO4 battery equipped with the p-SPA NS@PU separator demonstrated stable cycling for over 400 cycles under a high mass loading of 11.24 mg cm−2 at 3C, with a capacity retention of 91.4%.

KW - amphoteric polymer

KW - interfacial adhesion

KW - lithium metal batteries

KW - separator

UR - https://www.scopus.com/pages/publications/105032438515

U2 - 10.1002/adfm.202532094

DO - 10.1002/adfm.202532094

M3 - Article

AN - SCOPUS:105032438515

SN - 1616-301X

VL - 36

JO - Advanced Functional Materials

JF - Advanced Functional Materials

IS - 42

M1 - e32094

ER -