Abstract Optimized porous structure is a prerequisite for high performance Li‒O2 battery cathode. Macroporous-mesoporous carbon (MMC) is fabricated via a nano-replication method using mesoporous SiO2 (KIT-6) containing NiO as the template. By varying the amount of NiO in the KIT-6/NiO composite template, the amount of macropores inside MMC is easily controlled. The as-prepared MMC exhibits a highly porous structure with abundant ordered mesopores along with macropores that are larger than 200 nm in size. When the MMC is applied as the cathode material in a Li‒O2 battery, the cell exhibits greatly improved electrochemical performance in comparison to a cell using conventional ordered mesoporous carbon (OMC) without macropores. Systematic studies indicate that while mesopores in the OMC are clogged with Li2O2 formed during the early stage of discharge, the MMC sufficiently accommodates a large amount of Li2O2 in the pores. In addition, Li2O2 with poor crystallinity forms on the cathode containing MMC during subsequent discharge processes, which can be due to the accumulated side product and the limited size of pores. The formation of amorphous Li2O2 and the expedited mass transport through the interconnected meso- and macropores of MMC can attribute to the improved electrochemical performance of the MMC cathode material.

中文翻译：

---

通过为 Li-O 2 电池正极引入大孔改善有序介孔碳的电化学性能

摘要 优化的多孔结构是高性能 Li-O2 电池正极的先决条件。大孔-介孔碳 (MMC) 是通过纳米复制方法使用含有 NiO 作为模板的介孔 SiO2 (KIT-6) 制备的。通过改变 KIT-6/NiO 复合模板中 NiO 的数量，可以轻松控制 MMC 内的大孔数量。所制备的 MMC 具有高度多孔的结构，具有丰富的有序中孔和大于 200 nm 的大孔。当MMC用作Li-O2电池的正极材料时，与使用没有大孔的常规有序介孔碳（OMC）的电池相比，该电池的电化学性能大大提高。系统研究表明，虽然 OMC 中的中孔被放电早期形成的 Li2O2 堵塞，但 MMC 足以在孔中容纳大量的 Li2O2。此外，在随后的放电过程中，在含有 MMC 的阴极上会形成结晶度较差的 Li2O2，这可能是由于副产物的积累和孔隙尺寸的限制。无定形 Li2O2 的形成和通过 MMC 互连的中孔和大孔的加速传质可归因于 MMC 正极材料的电化学性能的提高。这可能是由于积累的副产品和孔的大小有限。无定形 Li2O2 的形成和通过 MMC 互连的中孔和大孔的加速传质可归因于 MMC 正极材料的电化学性能的提高。这可能是由于积累的副产品和孔的大小有限。无定形 Li2O2 的形成和通过 MMC 互连的中孔和大孔的加速传质可归因于 MMC 正极材料的电化学性能的提高。