Author(s) Park, J.S.; Jo, J.Hyeon; Yashiro, H.; Kim, S.S.; Kim, S.J.; Sun, Y.K.; Myung, S.T.
Journal ACS Appl Mater Interfaces
Date Published 2017 Jul 18
Abstract

Unlike SnO2, few studies have reported on the use of SnC2O4 as an anode material for rechargeable lithium batteries. Here, we first introduce a SnC2O4-reduced graphene oxide composite produced via hydrothermal reactions followed by a layer-by-layer self-assembly process. The addition of rGO increased the electric conductivity up to ~10-3 S cm-1. As a result, the SnC2O4-reduced graphene oxide electrode exhibited a high charge (oxidation) capacity of ~1166 mAh g-1 at a current of 100 mA g-1 (0.1 C-rate) with a good retention delivering approximately 620 mAh g-1 at the 200th cycle. Even at a rate of 10 C (10 A g-1), the composite electrode was able to obtain a charge capacity of 467 mAh g-1. In contrast, the bare SnC2O4 had inferior electrochemical properties relative to the SnC2O4 - reduced graphene oxide composite: ~643 mAh g-1 at the first charge, retaining 192 mAh g-1 at the 200th cycle and 289 mAh g-1 at 10 C. This improvement in electrochemical properties is most likely due to the improvement in electric conductivity, which enables facile electron transfer via simultaneous conversion above 0.75 V and de-/alloy reactions below 0.75 V: SnC2O4 + 2Li+ + 2e- → Sn + Li2C2O4 + xLi+ + xe- → LixSn on discharge (reduction) and vice versa on charge. This was confirmed by systematic studies of ex-situ X-ray diffraction, transmission electron microscopy, and time-of-flight secondary-ion mass spectroscopy.

DOI 10.1021/acsami.7b03325
ISSN 1944-8252
Citation ACS Appl Mater Interfaces. 2017.

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