Abstract Layered nickel oxides have been focused with intense research interests as high-performance lithium-ion batterie (LIB) anode. However, it is hard to obtain few layered nickel oxides material directly as it easily forms bulk material with the strong interaction between the interlayer. In this work, two-dimensional (2D) nickel-based coordination polymers were successfully prepared according to aqueous phase copolymerization approach. And then uniform carbon-doped NiO nanosheets were successfully obtained from facile solution assembly and post-thermal treatment. The detailed electrochemical testing shows that the uniform NiO nanocrystals encapsulated into porous N-doped carbon (NiO@NC) nanosheets present much higher rate capability with the discharge specific capacity of 782.7 mAh·g −1 at high current density of 2.0 A·g −1 than pure NiO (690 mAh·g −1 ). It also shows long-term cycling performance with 91% retention after 50 cycles at 1.0 A·g −1 . The high rate capability, cycling stability and the easy synthesis make NiO@NC nanosheets as a promising candidate for LIB anode and build up new way for the fabrication of metal oxides anode materials. Graphical abstract

中文翻译：

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用于高性能锂离子电池的多孔方形NiO@NC纳米片的高伪电容

摘要 层状氧化镍作为高性能锂离子电池 (LIB) 负极受到了广泛的研究兴趣。然而，很少有层状氧化镍材料很难直接获得，因为它很容易形成块状材料，中间层之间的相互作用很强。在这项工作中，根据水相共聚方法成功制备了二维（2D）镍基配位聚合物。然后通过简便的溶液组装和后热处理成功地获得了均匀的碳掺杂 NiO 纳米片。详细的电化学测试表明，包裹在多孔 N 掺杂碳 (NiO@NC) 纳米片中的均匀 NiO 纳米晶体具有更高的倍率性能，在 2 的高电流密度下放电比容量为 782.7 mAh·g -1。0 A·g -1 比纯NiO (690 mAh·g -1 )。它还显示出长期循环性能，在 1.0 A·g -1 下 50 次循环后保留率为 91%。高倍率性能、循环稳定性和易于合成使 NiO@NC 纳米片成为 LIB 负极的有希望的候选者，并为金属氧化物负极材料的制造开辟了新途径。图形概要