In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2014-01, No. 1 ( 2014-04-01), p. 9-9
Abstract:
Titanium dioxide (TiO 2 ), a candidate as anode active material for lithium ion batteries, has attracted much attention from researchers due to its safety characteristics arising from its high electrochemical potential (~1.5V) vs. Li/Li + , low cost, material availability and environmental benignity. However, low electric conductivity, sluggish Li + diffusivity and poor cycle performance of TiO 2 have limited its wide acceptance in practical rechargeable lithium ion batteries. Various strategies such as TiO 2 -C-nano metal composites [1], nanofibers [2] , and TiO 2 flakes [3], have been investigated in literature work. While these studies led to improved performance to various degrees, they were limited either in rate ( 〈 20C) or cycle life ( 〈 100 cycles) or both. A recent work [4] involved atomic layer deposition (ALD) of TiO 2 on graphene powders and demonstrated vastly improved rate and cycle capabilities of the resulting materials. Here we present an alternative and promising method of preparing extremely high rate and long cycle life anodes via ALD coatings of TiO 2 on mesoporous activated carbon (AC) electrodes. Figure 1 shows charge and discharge voltages between 1.5V and 3.0V (vs. Li/Li + ) of an ALD TiO 2 -AC and a mesoporous AC baseline coin half cell versus specific capacity based on total active materials. Conventional carbonate-based lithium ion electrolyte was used. The ALD TiO 2 -AC cell demonstrated nearly five-fold capacity increase against the baseline with voltage profiles typical of nano TiO 2 . The contribution of ALD TiO 2 to the observed capacity is ~83%, which leads to ~73 mAh/g specific capacity. The relatively low specific capacity is because of the 1.5V cutoff voltage used in this study. Figure 2 shows rate performance of ALD TiO 2 -AC vs. AC baseline half cells. The ALD TiO 2 -AC demonstrated very high rate capability, e.g. delivering 70% of low rate capacity at 400C rate, surpassing that of AC baseline. Figure 3 shows excellent cycle stability of ALD TiO 2 -AC half cell with 80% capacity retention after 800 cycles. The remarkable electrochemical performance demonstrated from ALD TiO 2 -AC is attributed to ALD enabled TiO 2 nano structure. Such nano structure is responsible for facile lithium insertion/extraction leading to extremely high rate capability and long cycle life due to stress/stain free nano architecture. The results in this study suggest a promising material processing methodology for high rate and long cycle life anodes for lithium ion batteries used in applications that require fast rate capability, when implemented with high throughput, high volume ALD processes. Figure 1. Charge and discharge voltage profiles of ALD TiO 2 -AC/Li vs. AC/Li baseline half cells. Figure 2. Rate capability tests of ALD TiO 2 -AC/Li vs. AC baseline half cells. Figure 3. Cycle life test of an ALD TiO 2 -AC/Li cell. References Song Gyun Lee, Honggui Deng, Jun Hu, Lihui Zhou, Honglai Liu, Int. J. Electrochem. Sci. , 8 , 2204 (2013). Zunxian Yang, Guodong Du, Qing Meng, Zaiping Guo, Xuebin Yu, Zhixin Chen, Tailiang Guo, and Rong Zeng, J. Mater. Chem. , 22 , 5848 (2012). Ming-Che Yang, Yang-Yao Lee, Bo Xu, Kevin Powers, Ying Shirley Meng, J. Power Sources , 207 , 166 (2012). Chunmei Ban, Ming Xie, Xiang Sun, Jonathan J Travis, Gongkai Wang, Hongtao Sun, Anne C Dillon, Jie Lian and Steven M George, Nanotechnology 24, 424002 (2013).
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2014-01/1/9
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2014
detail.hit.zdb_id:
2438749-6
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