PUB-2014-SAS

SnO2 Anode Surface Passivation by Atomic Layer Deposited HfO2 Improves Li Ion Battery Performance

N. Yesibolati, M. Shahid, F.M. Ross, M. Reuter, and H.N. Alshareef, “SnO2 Anode Surface Passivation by Atomic Layer Deposited HfO2 Improves Li Ion Battery Performance”​
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Volume 10, Issue 14pages 2849–2858July 23, 2014; Cover Page & VIP Paper

N. Yesibolati, M. Shahid, F.M. Ross, M. Reuter, and H.N. Alshareef
ALD, HfO2, Li Ion Battery
2014
​For the fi rst time, it is demonstrated that nanoscale HfO 2 surface passivation layers formed by atomic layer deposition (ALD) signifi cantly improve the performance of Li ion batteries with SnO 2 -based anodes. Specifi cally, the measured battery capacity at a current density of 150 mAg−1 after 100 cycles is 548 and 853 mAhg−1 for the uncoated and HfO 2 -coated anodes, respectively. Material analysis reveals that the HfO 2 layers are amorphous in nature and conformably coat the SnO 2 -based anodes. In addition, the analysis reveals that ALD HfO 2 not only protects the SnO2-based anodes from irreversible reactions with the electrolyte and buffers its volume change, but also chemically interacts with the SnO 2 anodes to increase battery capacity, despite the fact that HfO2 is itself electrochemically inactive. The amorphous nature of HfO 2 is an important factor in explaining its behavior, as it still allows suffi cient Li diffusion for an effi cient anode lithiation/delithiation process to occur, leading to higher battery capacity.