Improved Functionality of Lithium‐Ion Batteries Enabled by Atomic Layer Deposition on the Porous Microstructure of Polymer Separators and Coating Electrodes

Abstract

Atomic layer deposition (ALD) of Al 2 O 3 is applied on a polypropylene separator for lithium-ion batteries. A thin Al 2 O 3 layer ( < 10 nm) is coated on every surface of the porous polymer microframework without signifi cantly increasing the total separator thickness. The thin Al 2 O 3 ALD coating results in signifi cantly suppressed thermal shrinkage, which may lead to improved safety of the batteries. More importantly, the wettability of Al 2 O 3 ALD-coated separators in an extremely polar electrolyte based on pure propylene carbonate (PC) solvent is demonstrated, without any decrease in electrochemical performances such as capacity, rate capability, and cycle life. Finally, a LiCoO 2 /natural graphite full cell is demonstrated under extremely severe conditions (pure PC-based electrolyte and high (4.5 V) upper cut-off potential), which is enabled by the Al 2 O 3 ALD coating on all three components (cathode, anode, and separator).

Hollow mesoporous silica sphere-embedded composite separator for high-performance lithium-ion battery

“…More recently, surface coatings based on organic polymers, occasionally combined with inorganic ceramic fillers, such as SiO 2 , Al 2 O 3 , TiO 2 , and ZrO 2 , have attracted substantial attention because of their simplicity, effectiveness, and processing versatility [11][12][13][14][15][16]. Jung et al [12] coated a thin Al 2 O 3 layer on the PP separator by atomic layer deposition technology. Lee et al [13] prepared a Al 2 O 3 -coated PP separator using co-polyimide (PI) P84 as a polymeric binder.…”

Improving battery safety by early detection of internal shorting with a bifunctional separator

“…In the last few decades, considerable efforts have been devoted to suppressing dendrite growth by improving electrode materials 16,17 , electrolyte additives 18,19 , separators 9,[20][21][22][23] and battery management systems 8 with some success, although they still do not solve the problem. Typical examples are the re-engineering of the surface morphologies and coating processes of the electrodes 16,17,24 , modification of the electrolyte solvent and solute 18,19,[25][26][27][28] , incorporation of hard ceramic coatings onto the porous polymer separator 5,20,21,23 and theoretical modelling 29,30 of the mechanisms leading to dendrite formation.…”

“…Typical examples are the re-engineering of the surface morphologies and coating processes of the electrodes 16,17,24 , modification of the electrolyte solvent and solute 18,19,[25][26][27][28] , incorporation of hard ceramic coatings onto the porous polymer separator 5,20,21,23 and theoretical modelling 29,30 of the mechanisms leading to dendrite formation. Unfortunately, despite intense study for several decades, it seems nearly impossible to completely eliminate dendrite formation with current technologies, as the lithium re-deposition process is inherently non-uniform and predisposed to formation of dangerous lithium dendrites.…”

Study of the Mechanisms of Internal Short Circuit in a Li/Li Cell by Synchrotron X-ray Phase Contrast Tomography

“…Hitherto, no experiments have been reported in the battery community that aim at investigating the mechanisms of ISCs leading to (internal) cell degradation. Whilst different strategies have been proposed to avoid ISC-induced battery failures, [31][32][33][34][35][36][37][38] it remains of fundamental interest to directly visualize the ISC caused by growing LmSs in order to fundamentally understand the failure mechanism of LIBs and thereafter be able to improve their properties for current and future usage.…”