To deploy Li-ion batteries in next-generation vehicles, it is essential to develop electrodes with durability, high energy density, and high power. Here we report a breakthrough in controlled full-electrode nanoscale coatings that enables nanosized materials to cycle with durable high energy and remarkable rate performance. The nanoparticle electrodes are coated with Al(2)O(3) using atomic layer deposition (ALD). The coated nano-LiCoO(2) electrodes with 2 ALD cycles deliver a discharge capacity of 133 mAh/g with currents of 1400 mA/g (7.8C), corresponding to a 250% improvement in reversible capacity compared to bare nanoparticles (br-nLCO), when cycled at this high rate. The simple ALD process is broadly applicable and provides new opportunities for the battery industry to design other novel nanostructured electrodes that are highly durable even while cycling at high rate.

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).

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