The Role of Al₂O₃ ALD Coating on Sn‐Based Intermetallic Anodes for Rate Capability and Long‐Term Cycling in Lithium‐Ion Batteries

Abstract

The electrochemical performances of CoSn2 and Ni3Sn4 as potential anode materials in lithium‐ion batteries (LIBs) are investigated using varying thicknesses of an alumina layer deposited by the atomic layer deposition (ALD) technique. Rate capability results showed that at high current densities, Al2O3‐coated CoSn2 and Ni3Sn4 electrodes after 10‐ALD cycles outperformed uncoated materials. The charge capacities of coated CoSn2 and Ni3Sn4 electrodes are 571 and 134 mAh g−1, respectively, at a high current density of 5 A g−1, while the capacities of uncoated electrodes are 363 and 11 mAh g−1. When the current density is reduced to 1 A g−1, however, the cycling performances of Al2O3‐coated CoSn2 and Ni3Sn4 electrodes fade faster after almost 40 cycles than uncoated electrodes. The explanation is found in the composition of the solid‐electrolyte interface (SEI), which strongly depends on the current rate. Thus, X‐ray photoelectron spectroscopy analysis of SEI layers on coated samples cycles at a low current density of 0.1 Ag−1, revealed organic carbonates as major products, which probably have a low ionic conductivity. In contrast, the SEI of coated materials cycled at 5 Ag−1 consists mostly of mixed inorganic/organic fluorine‐rich Al‐F and C‐F species facilitating a higher ionic transport, which improves electrochemical performance.

In Situ Transmission Electron Microscopy for Sodium‐Ion Batteries

“…The improved cycling performance was ascribed to the fact that the ALD‐Al 2 O 3 coating can act as ion‐conductive nanoglue, robustly anchor the Sn NPs to the substrate, and retain the anode's structural integrity. [ 87 ]…”

“…The improved cycling performance was ascribed to the fact that the ALD-Al 2 O 3 coating can act as ion-conductive nanoglue, robustly anchor the Sn NPs to the substrate, and retain the anode's structural integrity. [87] Bi belongs to the VA group and shows similar chemical properties to P and Sb. Due to the unique layered structure, Bi is a promising alloying-type negative electrode material in SIBs.…”

Rational Design and Engineering of 1D Heterostructured Porous Sn/CoSnx@C Nanotubes for Superior Lithium Storage

“…In particular, lithium-ion batteries (LIBs) have become one of the most important energy storage methods in contemporary times owing to their high energy density, no memory defect, and suitable working potential . At present, LIBs have been implemented in many electronic devices, for instance, electric vehicles, UAVs, laptops, and mobile phones. − However, the low capacity and poor cycling performance have seriously hindered the development of LIBs; researching electrode materials with high energy density and long cycle life is a top priority for LIBs. , Tin, an alloy-type anode material, is a good candidate for lithium storage because of its much higher theoretical capacity (992 mAh g –1 ) than commercial graphite (372 mAh g –1 ) and good conductivity but has been limited by the large volume changes (>200%) during the lithiation/delithiation process, leading to mechanical fracture and subsequent rapid capacity attenuation, hindering the lithium storage performance. − …”