Flexible, high-voltage, ion-conducting composite membranes with 3D aramid nanofiber frameworks for stable all-solid-state lithium metal batteries

Abstract

The practical application of solid polymer electrolytes in high-energy Li metal batteries is hindered by Li dendrites, electrochemical instability and insufficient ion conductance. To address these issues, flexible composite polymer electrolyte (CPE) membranes with three dimensional (3D) aramid nanofiber (ANF) frameworks are facilely fabricated by filling polyethylene oxide (PEO)-lithium bis(trifluoromethylsulphonyl)imide (LiTFSI) electrolyte into 3D ANF scaffolds. Because of the unique composite structure design and the continuous ion conduction at the 3D ANF framework/PEO-LiTFSI interfaces, the CPE membranes show higher mechanical strength (10.0 MPa), thermostability, electrochemical stability (4.6 V at 60°C) and ionic conductivity than the pristine PEO-LiTFSI electrolyte. Thus, the CPEs display greatly improved interfacial stability against Li dendrites (≥1000 h at 30°C under 0.10 mA cm −2), compared with the pristine electrolyte (short circuit in 13 h). The CPE-based all-solid-state LiFePO 4 /Li cells also exhibit superior cycling performance (e.g., 130 mA h g −1 with 93% retention after 100 cycles at 0.4 C) than the ANF-free cells (e.g., 82 mA h g −1 with 66% retention). This work offers a simple and effective way to achieve high-performance composite electrolyte membranes with 3D nanofiller framework for promising solid-state Li metal battery applications.

Advanced energy materials for flexible batteries in energy storage: A review

“…Different kinds of organic and inorganic components have been used in inorganic/organic composite electrolytes to explore possibilities of enhancing ionic conductivity, broadening voltage window, and improving electrode/ electrolyte interfacial compatibility. 18,[208][209][210][211][212][213][214] However, the flexible batteries with composite electrolytes under commercially required tests are rather limited, since the materials, structure, and configuration design still cannot withstand significant deformation, especially taking energy density and safety into considerations.…”

“…[11][12][13][14][15][16] Such a paradigm shift arises from the breakthroughs in materials and processing techniques, rendering and creating diverse opportunities to integrate electrochemical energy into flexible devices. [17][18][19][20] Flexible batteries have been the research of interest due to their potential to enable electronic products more bendable, adaptable, and comfortable. [21][22][23][24][25] These versatile functionalities stimulate the development of Internet of things (IoT), roll-up displays, implantable medical robots, wearable electronics.…”

Modulating composite polymer electrolyte by lithium closo-borohydride achieves highly stable solid-state battery at 25°C

“…Solid-state lithium batteries (SSLBs) have attracted considerable attention owing to their potential to mitigate safety issues associated with organic liquid electrolytes, such as leakage, flammability, and short circuiting (via dendritic growth) of the batteries [1][2][3][4]. Solid electrolytes play a crucial role in the overall electrochemical performance of SSLBs.…”

Boosting the Performance of Solid‐State Lithium Battery Based on Hybridizing Micron‐Sized LATP in a PEO/PVDF‐HFP Heterogeneous Polymer Matrix

“…The -HFP group containing F atom with strong electronegativity can enlarge the amorphous region in polymer matrix, which can facilitate for higher concentration of charge carriers, and capture lithium ions to migrate within the disorder region. [22] However, low mechanical strength of PVDF-HFP electrolytes is an obstacle to membrane processing. [23,24] Apparently, each polymer matrix has its advantages and disadvantages.…”