枣碳改性MnO_(2)锌锰电池正极材料性能研究

Research on performance of jujube carbon modified MnO_(2) cathode for zinc-manganese batteries

中性水系锌锰电池因具有低成本、绿色环保等优势在储能领域具有重要的应用前景,提高其正极材料MnO_(2)的导电性能,从而实现良好的倍率性能和循环性能,是实现该电池体系大规模应用的关键问题之一。文中以冷冻干燥的大枣(DGZ)为前驱体,通过预碳化和活化工艺制备多孔碳材料(C-DGZ),进而在水热条件下将其与KMnO_(4)反应,原位制备得到α-MnO_(2)/C-DGZ复合材料。由于冻干枣碳的三维导电网络为电子传输提供了有效通道,复合后的α-MnO_(2)/C-DGZ作为锌锰电池正极表现出高的容量和良好的循环性能,在1 A/g的电流密度下循环400圈后比容量高达305 mAh/g。即使在3 A/g的电流密度下循环1000圈,α-MnO_(2)/C-DGZ比容量仍保持在82 mAh/g。此研究为生物质碳材料应用于锌锰电池提供借鉴作用。

Neutral aqueous zinc-manganese batteries have important application prospects in the field of energy storage due to their low cost,environmental friendlyness.Improving the conductivity of MnO_(2)cathode materials to obtain good rate performance and cycle performance is one of the key problems to realize the large-scale application.Porous carbon materials(C-DGZ)was synthesized by using freeze-dried jujube(DGZ)as precursor through a pre-carbonization and activation process,which further reacted with KMnO_(4) under hydrothermal condition to prepareα-MnO_(2)/C-DGZ composite.Since the three-dimensional conductive network of freeze-dried jujube carbon provides an effective channel for electron transmission,α-MnO_(2)/C-DGZ cathode exhibits high capacity and good cycle performance for zinc-manganese batteries.A high specific capacity of 305 mAh/g is retained for the 400 cycles at a current density of 1 A/g.Even at a high current density of 3 A/g,a capacity of 82 mAh/g is achieved after 1000 cycles.This research provides a guideline for the application of biomass carbon materials in zinc-manganese batteries.