Li4Ti5O12/石墨烯纳米带复合材料作为锂离子电池的阳极

Li4Ti5O12/graphene nanoribbons composite as anodes for lithium ion batteries.

作者信息

Medina P A, Zheng H, Fahlman B D, Annamalai P, Swartbooi A, le Roux L, Mathe M K

机构信息

Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mount pleasant, Michigan, 48858 USA.

Material Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), PO BOX 395, Pretoria, 0001 South Africa.

出版信息

Springerplus. 2015 Oct 26;4:643. doi: 10.1186/s40064-015-1438-0. eCollection 2015.

DOI:10.1186/s40064-015-1438-0

PMID:26543777

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4627983/

Abstract

In this paper, we report the synthesis of a Li4Ti5O12/Graphene Nanoribbons (LTO/GNRs) composite using a solid-coating method. Electron microscope images of the LTO/GNRs composite have shown that LTO particles were wrapped around graphene nanoribbons. The introduction of GNRs was observed to have significantly improved the rate performance of LTO/GNTs. The specific capacities determined of the obtained composite at rates of 0.2, 0.5, 1, 2, and 5 C are 206.5, 200.9, 188, 178.1 and 142.3 mAh·g(-1), respectively. This is significantly higher than those of pure LTO (169.1, 160, 150, 106 and 71.1 mAh·g(-1), respectively) especially at high rate (2 and 5 C). The LTO/GNRs also shows better cycling stability at high rates. Enhanced conductivity of LTO/GNRs contributed from the GNR frameworks accelerated the kinetics of lithium intercalation/deintercalation in LIBs that also leads to excellent rate capacity of LTO/GNRs. This is attributed to its lower charge-transfer resistance (Rct = 23.38 Ω) compared with LTO (108.05 Ω), and higher exchange current density (j = 1.1 × 10(-3) mA cm(-2))-about 20 times than those of the LTO (j = 2.38 × 10(-4) mA cm(-2)).

摘要

在本文中，我们报道了采用固体包覆法合成Li4Ti5O12/石墨烯纳米带（LTO/GNRs）复合材料。LTO/GNRs复合材料的电子显微镜图像显示，LTO颗粒包裹在石墨烯纳米带上。观察到引入GNRs显著提高了LTO/GNTs的倍率性能。所制备的复合材料在0.2、0.5、1、2和5 C倍率下测定的比容量分别为206.5、200.9、188、178.1和142.3 mAh·g(-1)。这明显高于纯LTO的比容量（分别为169.1、160、150、106和71.1 mAh·g(-1)），尤其是在高倍率（2和5 C）下。LTO/GNRs在高倍率下也表现出更好的循环稳定性。GNR框架提高了LTO/GNRs的导电性，加速了锂离子电池中锂嵌入/脱嵌的动力学，这也导致LTO/GNRs具有优异的倍率性能。这归因于其与LTO（108.05 Ω）相比更低的电荷转移电阻（Rct = 23.38 Ω），以及更高的交换电流密度（j = 1.1×10(-3) mA cm(-2)）——约为LTO（j = 2.38×10(-4) mA cm(-2)）的20倍。