Contents lists available at ScienceDirect Solid State Ionics journal homepage: www.elsevier.com/locate/ssi Ethylene glycol combustion strategy towards 3D mesoporous ZnCo 2 O 4 as anodes for Li-ion batteries Zhongchun Li a, ⁎ ,1 , Di Wang a,1 , Aijun Gu a , Wenxian Wei b , Hongying Lv a , Zhengsong Lou a , Quanfa Zhou c, ⁎ a School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, PR China b Testing center, Yangzhou University, Yangzhou 225009, PR China c Changzhou Institute of Technology, Changzhou 213032, PR China ARTICLE INFO Keywords: Ethylene glycol combustion ZnCo 2 O 4 Mesoporous Li-ion batteries ABSTRACT A facile and fast ethylene glycol combustion strategy was developed to the synthesis of three-dimension (3D) mesoporous ZnCo 2 O 4 architectures. It was found that the volume of colloidal silica employed in the combustion system exerts a profound impact on the specifc surface area (SSA) and pore volume of 3D porous ZnCo 2 O 4 . The SSA and pore volume of 3D mesoporous ZnCo 2 O 4 –400 could reach up to 130 m 2 g −1 and 0.641 cm 3 g −1 when 400 μL of colloidal silica was used in the combustion system. When used as the LIB's anodes, the 3D mesoporous ZnCo 2 O 4 –400 could show high reversible capacity and superior cycling performance. The excellent performance is attributed to the high SSA and abundant mesoporous structures in the 3D mesoporous ZnCo 2 O 4 –400 archi- tectures. The present work not only ofers a novel synthetic route towards 3D mesoporous ZnCo 2 O 4 but also demonstrates the vast prospect of 3D mesoporous ZnCo 2 O 4 as the anode material for Li-ion batteries (LIBs). 1. Introduction With the rapid depletion of fossil sources and environmental dete- rioration, various energy storage devices such as LIBs and redox fow batteries have been extensively investigated [1–3]. LIBs are the typical energy storage device for portable electronics and electric vehicles [4,5]. The energy storage performances of LIBs directly depend on the electrode materials, thereby developing versatile electrode materials to boost energy density and cycling stability has become a key topic for LIBs [6–8]. The commercial graphite adopted as anode materials gen- erally sufers from its low capacity and rate performance [9,10], which hinders the large-scale application of LIBs. Preparing excellent anode materials is of vital importance to deliver high capacity and cycling stability. In the past decades, great eforts have been devoted to de- veloping various metal oxides, especially spinel bimetal oxides with diferent morphologies as alternative anode materials for LIBs [11–15]. Among various spinel oxides, ZnCo 2 O 4 has captured great concern due to its environmental benignity, afordable price, good conductivity, and high theoretical capacity [16–18]. Up to now, various routes have been explored to prepare ZnCo 2 O 4 with diferent morphologies such as na- norods [19], microspheres [20], octahedrons [17], bundle structures [21], nanosheets/nanofakes [22,23], sliced orange-shape [24], nanocubes [25], and hollow polyhedrons [26] as anodes for LIBs. De- spite great achievements have been made, the tremendous change in volume resulted from continuous cycles leads to fast capacity decaying, which greatly impedes their large-scale application. Fabricating hollow architectures has been confrmed to be an ef- fective way to improve capacity and cycling stability, especially those with plentiful mesoporous structures [27,28]. The uniform mesoporous structure can not only provide short lithium ions difusion length, and high contact area, but also ofer enough reservoirs to bufer the stress resulted from drastic volume change, thereby promoting energy storage performance [29]. For instance, Huang's group applied PVP-assisted solvothermal process to synthesize fower-like ZnCo 2 O 4 microspheres with multimodal pores, which provided a reversible capacity of 856 mAh g −1 after 1000 cycles at 1C [30]. Zhen et al. employed a hydro- thermal route to form mesoporous ZnCo 2 O 4 nanosheets. After 200 cy- cles at 1 A g −1 , the specifc capacity kept at about 810 mAh g −1 [31]. Despite great gains in material synthesis, there is still lack of an efec- tive method to batch-scale synthesis of mesoporous ZnCo 2 O 4 with large SSA and suitable pore size. As we all know, the solution combustion method is a facile route with a low-cost and short time for the massive preparation of porous architectures [32–34]. However, it is hard to produce metal oxide https://doi.org/10.1016/j.ssi.2020.115461 Received 12 April 2020; Received in revised form 12 August 2020; Accepted 10 September 2020 ⁎ Corresponding authors. E-mail addresses: czlizc@126.com (Z. Li), zqf@czu.cn (Q. Zhou). 1 These authors contributed equally to this work. Solid State Ionics 356 (2020) 115461 Available online 21 September 2020 0167-2738/ © 2020 Elsevier B.V. All rights reserved. T