Li Zongtang, Lian Xiao, Wu Mingzai, Zheng Fangcai, Gao Yuanhao, Niu Helin
Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, College of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, China.
Dalton Trans. 2020 May 28;49(20):6644-6650. doi: 10.1039/d0dt00980f. Epub 2020 May 5.
Manganese dioxide (MnO) is a high-performance anodic material and applied widely in lithium-ion batteries (LIBs). However, some intrinsic limitations originate from the low ionic conductivity, high polarization, and severe volume expansion of this type of material. In this work, we generated a one-dimensional porous MnO@CoO composite from a MnOOH@ZIF-67 precursor, which is synthesized via a self-assembly strategy. The one-dimensional porous structure provided more active sites and shorter-ion/electron-diffusion distance, thereby enabling higher Li storage capacity and better rate capability than a transition metal oxide alone. The CoO coating buffered the volume change during Li insertion/extraction, leading to increased cycling stability of the electrode. When evaluated as the anode of LIBs, MnO@CoO exhibited a reversible capacity of 647 mA h g at 2000 mA g after 400 cycles. This excellent performance indicated that the MnO@CoO material could be an attractive potential candidate for Li storage.
二氧化锰（MnO）是一种高性能阳极材料，在锂离子电池（LIBs）中得到广泛应用。然而，这类材料存在一些固有局限性，如离子电导率低、极化程度高以及严重的体积膨胀。在本研究中，我们通过自组装策略合成了MnOOH@ZIF-67前驱体，进而制备出一维多孔MnO@CoO复合材料。一维多孔结构提供了更多的活性位点以及更短的离子/电子扩散距离，因此与单一过渡金属氧化物相比，具有更高的锂存储容量和更好的倍率性能。CoO涂层缓冲了锂嵌入/脱出过程中的体积变化，提高了电极的循环稳定性。当作为LIBs的阳极进行评估时，MnO@CoO在400次循环后，于2000 mA g电流密度下展现出647 mA h g的可逆容量。这一优异性能表明，MnO@CoO材料有望成为极具吸引力的锂存储候选材料。
