锰掺杂二氧化钛纳米片为正极催化剂制备高性能锂空气电池

Synthesis of Manganese-Doped TiO2 Nanosheet as Cathode Catalyst for Rechargeable Lithium–Oxygen Batteries with High Performance

摘要:

由于锂空气电池具有超高理论能量密度、低污染、零排放等特点,其在电动汽车方面具有良好的应用前景,因而吸引了全球众多研究者的关注。但其主要的问题是正极上的氧还原反应(ORR)和氧析出反应(OER)过程的钝化,导致放电性能和循环性能欠佳。本实验通过以Mn掺杂TiO₂作为正极催化剂,提高锂空气电池的电化学性能。首先,通过简便的水热方法处理煅烧过的金红石制备Mn-TiO₂；第二,将聚偏氟乙烯(PVDF)溶于N-甲基-2-吡咯烷酮(NMP)溶剂中,然后将KB和Mn-TiO₂与PVDF/NMP溶液混合,制备正极悬浮液。最后, 将正极悬浮液涂覆到碳纸上(直径 = 15 mm),并在60℃烘箱里烘干3h,获得空气正极。循环伏安法(CV)的结果表明,以Mn-TiO₂和KB为催化剂的正极具有较高的峰值电流密度。

Abstract:

Due to their superior theoretical energy density and low to zero emissions etc, rechargeable lithium-air batteries have attracted significant attention as promising next-generation power sources for vehicle applications. But the main challenge is the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) on the cathode, which results in poor discharge performance and cyclability. In this work, we propose using Mn doped TiO₂ as cathode catalyst to improve the electrochemical performance of lithium-air batteries. Firstly, rutile Mn-TiO₂ was calcined by a facile hydrothermal treatment method. Secondly, Polyvinylidene fluoride (PVDF) was dissolved in an N-methyl-2-pyrrolidone (NMP) solvent. KB and Mn-TiO₂ were mixed with a PVDF/NMP solution to fabricate a cathode slurry. The last, the cathode slurry was coated onto circular carbon paper (diameter = 15 mm) and dried at 60 ℃ 3 hours in the oven to obtain the air cathode, And the cyclic voltammetry (CV) results show that the cathode withSMn-TiO₂ with KB as catalysts exhibits a higher peak current density.