A highly efficient surface modified separator fabricated with atmospheric atomic layer deposition for high temperature lithium ion batteries

Abstract

Summary A high throughput mass production of separator is proposed using a well‐established unique in‐house process of roll‐to‐roll atmospheric atomic layer deposition. An ultra‐thin conformal layer of Al2O3 is deposited over the commercial Celgard (PE/PP/PE) using multi‐slit gas source head. Overall 10 nm increase is incurred in the thickness, while maintaining the porosity to ~48%. The entire process of fabrication was performed at very low temperature of 90°C. The high thermal stability of as‐modified separator is achieved at of 180°C. The separator was analyzed using X‐ray photoelectron spectrometer, electrochemical impedance spectra, and field emission scanning electron microscope. The as‐developed separator showed excellent wettability due to the surface medication in addition to robust flexibility, high conformity, and minimal thermal shrinkage. The Lithium cobalt oxide (LCO)/Graphite cells with atomic layer deposition (ALD) Celgard (Al2O3 deposited) separator delivered remarkable discharge capacity with 79.5% capacity retention after 100 cycles at 1 C as compared to the uncoated‐separator(Celgard separator), which yielded relatively less retention of ~70%. Moreover, the LCO/Graphite cells with the ALD‐Celgard separator delivered the discharge capacity of 140 mAh/g at elevated temperature (up to 80°C).

A highly efficient composite separator embedded with colloidal lanthanum oxide nanocrystals for high‐temperature lithium‐ion batteries

“…Moreover, by introducing the colloidal La 2 O 3 nanocrystals in PVDF‐HFP matrix also suppresses the strong vibrations bands between 400 and 800 cm −1 related to α and β crystalline phases in PVDF‐HFP 47‐50 . The reduction in peaks corresponding to α and β crystalline phases assures the more amorphous nature of composite separator which helps to improve the electrolyte uptake and further improvement in ionic conductivity 51‐53 . The strain‐stress curves of commercial, PVDF‐HFP and proposed separators are given in Figure 2D.…”

A Rational Design for a High‐Safety Lithium‐Ion Battery Assembled with a Heatproof–Fireproof Bifunctional Separator

“…reported a multilayer separator with an ultrathin 5 nm Al 2 O 3 layer through a novel roll‐to‐roll atmospheric ALD technology, which showed excellent flexibility, high conformity, suppressed thermal shrinkage, high electrolyte wettability, and improved tensile strength. [ 15 ] Despite these advantages, the relatively low productivity and high cost, as compared to ceramic‐coated separators, may limit its commercial application.…”

“…Lee et al reported a multilayer separator with an ultrathin 5 nm Al 2 O 3 layer through a novel roll-to-roll atmospheric ALD technology, which showed excellent flexibility, high conformity, suppressed thermal shrinkage, high electrolyte wettability, and improved tensile strength. [15] Despite these advantages, the relatively low productivity and high cost, as compared to ceramic-coated separators, may limit its commercial application. Herein, our high thermal stability CCS@PFR separator, which was prepared by further modifying single-side ceramiccoated separator with a 3D PFR-coated layer throughout the entire separator, was chosen as a substrate separator.…”

Robust Fluidic Biocompatible Strain Sensor Based on PEDOT:PSS/CNT Composite for Human-wearable and High-end Robotic Applications

“…Over the past few years, flexible electronics has significantly captured researchers' attention owing to its myriad applications, including physiological monitoring, (1)(2)(3) wearable electronics, (4)(5)(6) medical devices, protheses, smart clothes, and soft robotics. (7)(8)(9) In flexible devices, soft strain sensors play a major role owing to their vibrant features, such as high compliance, low weight, long lifetime, low cost, and the ability to sense the complex movements of soft robots and human body parts. (10) Unlike conventional sensors with rigid electronic subsystems and a limited sensing range, the robust design structure of soft sensors makes them ideal as an integral part of such high-end feedback applications.…”