Heterojunction‐Accelerating Lithium Salt Dissociation in Polymer Solid Electrolytes

Abstract

The practical application of solid‐state lithium‐metal batteries (SSLMBs) based on polymer solid electrolytes has been hampered by their low ion conductivity and lithium‐dendrite‐induced short circuits. This study innovatively introduces 1D ferroelectric ceramic‐based Bi4Ti3O12‐BiOBr heterojunction nanofibers (BIT‐BOB HNFs) into poly(ethylene oxide) (PEO) matrix, constructing lithium‐ion conduction highways with “dissociators” and “accelerating regions.” BIT‐BOB HNFs, as 1D ceramic fillers, not only can construct long‐range organic/inorganic interfaces as ion transport pathways, but also install “dissociators” and “accelerating regions” for these pathways through the electric dipole layer and built‐in electric field of BIT‐BOB HNFs, promoting the dissociation of lithium salts and the transfer of lithium ions. The working mechanisms of BIT‐BOB HNFs in the polymer matrix are verified by experimental tests and density functional theory calculations. The obtained composite solid electrolytes exhibit excellent lithium‐ion conductivity and migration number (6.67 × 10−4 S cm−1 and 0.54 at 50 °C, respectively). The assembled lithium symmetric battery achieves good cycling stability of over 4500 h. The LiFePO4||Li full battery delivers a high Coulombic efficiency (>99.9%) and discharge capacity retention rate (>87%) after 2200 cycles. In addition, the prepared composite polymer solid electrolyte demonstrates good practical application potential in flexible pouch batteries.

Design of Ultrathin Asymmetric Composite Electrolytes for Interfacial Stable Solid-State Lithium-Metal Batteries

“…Initially, the incorporation of LLZO nanofibers decreases the degree of crystallinity in the polymer matrix, hence enhancing the ionic conductivity. 27 Furthermore, the LLZO nanofibers' significant aspect ratio facilitates the creation of a rapid conduction pathway, allowing for efficient long-distance transportation of Li + . 28 It should be emphasized that, despite the similarity in ionic conductivity of the electrolyte, the variation in thickness results in a discrepancy in migration distance.…”

Interface‐Targeting Carrier‐Catalytic Integrated Design Contributing to Lithium Dihalide‐Rich SEI toward High Interface Stability for Long‐Life Solid‐State Lithium‐Metal Batteries

“…Comprehensive simulations and characterizations reveal the critical role of Brthiophene unit in POP, in which the unique structure design not only improve the efficiency of electron transfer, make CÀ Br easier break, but also facilitates the cleavage of CÀ F bond of TFSI À . Therefore, the dihalide LiF-LiBr were in situ [48][49][50][51][52][53][54][55][56]…”

“…[32] The weight ratio of filler was further investigated for the optimization of the ionic conductivity of the electrolyte. Figure S7 shows the EIS results of the SPE membrane under the frequency from 0.1 Hz to 1 MHz at various temperatures (30,40,50, and 60 °C). It can be found that the ionic conductivity varies linearly with temperature.…”

“…Figure 5. a) Cycling performances of LFP/SPE/Li batteries at 0.5.C. b) Comparison of comprehensive performance of pouch cell with related reported CSEs [48][49][50][51][52][53][54][55][56]. c) Cycling performances of LFP/SPE/Li pouch cell at 0.2 C. d) The corresponding voltage profiles of pouch cell at 0.2 C. e) Cycling performances of NCM811/PEO-Br-TPOM/Li battery at 0.5 C. f) Cycling performance of the pouch-type cell under extreme conditions.…”

Facile Construction of Flexible Pitch@PAN Heterojunction Nanofibers with Excellent Conductivity Performance Based on Spontaneous Phase Separation Spinning Technology

“…In recent years, wearable electronic products have attracted widespread attention from researchers due to their flexible and portable characteristics, which are in line with the future development direction of intelligence. , To further improve the practicality of flexible wearable products, these intelligent fiber materials are usually endowed with certain integrated functions such as elastic modulus, mechanical strength, conductivity, thermal conductivity, biocompatibility, and breathability. − Among them, coaxial heterojunction fibers with a core–shell structure are easy to integrate multiple functions, which have huge advantages in the wearable field. , At present, heterojunction fibers are mainly achieved through coaxial double-jet electrospinning technology, nanofiber interface coating modification, and other methods. − However, these methods are complex and difficult to scale up, greatly limiting their further application. Therefore, the exploratory research of facile construction strategies for heterojunction fibers has important academic research significance and practical value for market applications.…”