Separators play a crucial role in ensuring the safety of lithium-ion batteries (LIBs). Commercial polyolefin-based separators such as polyethylene (PE) still possess serious safety risks under abuse conditions because of their poor thermal stability. In this work, a novel type of binder-free, thin ceramic-coated separators with superior safety characteristics is demonstrated. A thin layer of alumina (Al 2 O 3 ) is coated on commercial PE separators using the electron-beam physical vapor deposition (EB-PVD) technique. Scanning electron microscopy (SEM), contact angle, impedance spectroscopy, and adhesion test techniques were employed to evaluate structure–property correlations. When compared to commercial slurry-coated separators, the EB-PVD-coated separators display (i) higher thermal stability, (ii) stronger ceramic–polymer adhesion, and (iii) competitive electrochemical performance of full LIB cells. Thermal stability, in terms of improved shutdown and breakdown characteristics of the separator, was studied using the in situ impedance technique up to 190 °C. In addition, the improved adhesion of the ceramic layer deposited on the PE separator was studied following the tape adhesion strength test. We prove that the thin (binder-free) ceramic layer coated by EB-PVD is far more effective in improving separator safety than those made using the conventional thick slurry coating.

Lithium-ion batteries (LIBs) have transformed modern electronics and rapidly advancing electric vehicles (EVs) due to their high energy and power densities, cycle-life, and acceptable safety. However, the comprehensive commercialization of EVs necessitates the invention of LIBs with much enhanced and stable electrochemical performances, including higher energy/power density, cycle-life, and operational safety, but at a lower cost. Herein, we report a simple method for improving the high-voltage (up to 4.5 V) charge capability of LIBs by applying a Li+-ion-conducting artificial cathode–electrolyte interface (Li+-ACEI) on the state-of-the-art cathode, LiCoO2 (LCO). A superionic ceramic single Li+ ion conductor, lithium aluminum germanium phosphate (Li1.5Al0.5Ge1.5(PO4)3, LAGP), has been used as a novel Li+-ACEI. The application of Li+-ACEI on LCO involves a scalable and straightforward wet chemical process (sol–gel method). Cycling performance, including high voltage charge, of bare and LAGP-coated cathodes has been determined against the most energy-dense anode (lithium, Li metal) and state-of-the-art carbonate-based organic liquid electrolyte (OLE). The application of an LAGP-based Li+-ACEI on LCO displays many improvements: (i) reduced charge-transfer and interfacial resistance; (ii) higher discharge capacity (167.5 vs 155 mAh/g) at 0.2C; (iii) higher Coulombic efficiency (98.9 vs 97.8%) over 100 cycles; and (iv) higher rate capability (143 vs 80.1 mAh/g) at 4C. Structural and morphological characterizations have substantiated the improved electrochemical behavior of bare and Li+-ACEI LCO cathodes against the Li anode.

Most space missions utilize energy storage, such as a rechargeable battery onboard the spacecraft. Therefore, a continuing evolution of battery performance can benefit a wide gamut of space science missions conducted or planned by NASA and worldwide space agencies. Venus presents the most significant challenge to energy storage systems due to a combination of high temperature (465 °C) and the presence of corrosive gases (CO 2 , CO, SO 2 , and N 2 ). On a NASA-funded project, a high-temperature (465 °C) lithium−selenium (Li∥Se) battery consisting of an anode of molten Li, a lithium-ion conducting ceramic electrolyte (garnet-type Li 6.4 Al 0.2 La 3 Zr 2 O 12 , LLZO), and a cathode of Se have been conceptualized. The proof-of-concept Li∥Se cells were built using baseline cell electrodes, electrolytes, and cell design. The fabricated Li∥Se cell was tested in an in-house built cell holder placed in an argon-filled glovebox. Electrochemical testing includes time-dependent open-circuit voltage measurements across a wide temperature range (230−500 °C) and electrochemical cycling at multiple current rates at 465 °C. Further cell components and design optimization will enable higher current charge−discharge and a longer battery life span over a wide temperature range. In addition, the use of high-energy electrodes will encourage longduration and safe Venus surface exploration.

Wearable electronics are playing an important role in the health care industry. Wearable sensors are either directly attached to the body surface or embedded into worn garments. Textile-based batteries can help towards development of body conformal wearable sensors. In this letter, we demonstrate a 2D planar textile-based primary Ag2O–Zn battery fabricated using the stencil printing method. A synthetic polyester woven fabric is used as the textile substrate and polyethylene oxide material is used as the separator. The demonstrated battery achieves an areal capacity of 0.6 mAh/cm2 with an active electrode area of 0.5 cm × 1 cm.

An unprotected cathode of a lithium-ion battery (LIB) cell using lithium metal anode and organic carbonate liquid electrolyte undergoes a significant structural damage during cycling (Li+ intercalation/ deintercalation) process. Also, a bare cathode in contact with liquid electrolyte forms a resistive cathode electrolyte interface (CEI) layer. Both the cathode structure damage and CEI lead to rapid capacity fade [1]. Cathode surface modification has been used to reduce CEI formation and structural damage that in turn improves capacity retention, cycle life, energy density, power density, and safety of a LIB.Recently, the coating of the cathode with an intermediate layer (IL) which is transparent to Li+ conduction but impermeable to electrolyte solvent has been developed to minimize CEI formation and structural damage. IL based on Li+ insulating ceramics such as aluminum oxide (Al2O3), tin oxide (SnO2), and magnesium oxide (MgO) has been developed but to a limited success in mitigating the above cathode degradation. The limited success of Li+ insulating coating relates to limited thickness of coating because resistance of coating layer increases with thickness of IL.To overcome the challenges associated with Li+ insulating IL, recently, Li+ conducting IL (solid-state ceramic electrolytes) has been explored. Some of the most studied ceramic solid electrolytes include lithium niobate (LNO), lithium lanthanum zirconium oxide (LLZO), lithium aluminum titanium phosphate (LATP), etc. Though, LNO (σ = 10-5 mS.cm-1) and LLZO (σ = 10-4 mS.cm-1), LATP (σ = 10-4 mS.cm-1) are better Li+ conductor compared to complete Li+ insulating ILs [2] (Al2O3, MgO, SnO2) but still not adequate for high performance LIB.Lithium aluminum germanium phosphate (LAGP- Li1.5Al0.5Ge1.5(PO4)3 ) has one order higher Li+ conduction (σ = 10-3 S.cm-1) compared to LATP [3]. Thus, we present LIB performance improvement through application of LAGP as IL on lithium cobalt oxide cathode (LCO) (Fig. 1). Figure 1 shows rate capability of LAGP coated LCO vs. pristine LCO, LNO and LLZO coated cathode. We will present a sol-gel as an economical and scalable method to apply LAGP thin-film as IL on LCO. Also, impedance, and storage induced cell degradation will be presented.REFERENCES[1] Joshua P. Pender, Gaurav Jha, Duck Hyun Youn, Joshua M. Ziegler, Ilektra Andoni, Eric J. Choi, Adam Heller, Bruce S. Dunn, Paul S. Weiss, Reginald M. Penner, and C. Buddie Mullins, Electrode Degradation in Lithium-Ion Batteries, ACS Nano 2020, 14, 1243−1295[2] Jeffrey W. Fergus, Ceramic and polymeric solid electrolytes for lithium-ion batteries, Journal of Power Sources195 (2010) 4554–4569[3] B. Kumar, D. Thomas, and J. Kumar, Space-Charge-Mediated Superionic Transport in Lithium Ion Conducting Glass-Ceramics, Journal of The Electrochemical Society, 156(7) A506-A513 (2009)Figure 1. Rate capability test of LCO cathode with LAGP, LNO and LLZO coating. Cathode performance in a half-cell (Li/1MLiPF6/LCO with or without IL) set up. Figure 1