Song Tian-Bing, Ma Qian-Li, Wang Bao-Juan, Zhang Xi-Rong, Wang Yong-Gang, Xiong Huan-Ming
Department of Chemistry, Shanghai Key Laboratory of Electrochemical and Thermochemical Conversion for Resources Recycling, Fudan University, Shanghai, 200438, China.
Angew Chem Int Ed Engl. 2025 Aug 18;64(34):e202503655. doi: 10.1002/anie.202503655. Epub 2025 Jun 30.
Carbon dots (CDs) have been explored widely in the electrochemistry field, owing to their unique structures and rich properties. However, in the reported devices, such as batteries and supercapacitors, CDs are always used as additives to modify the electrodes or regulate the electrolytes because they have been regarded as inert and low-capacity materials all along. Here, for the first time, o-phenylenediamine derived CDs are selected as the only protagonist to construct cathode materials for aqueous zinc-ion batteries (ZIBs). Such CDs (p-CDs) have a special π-conjugated phenazine-based structure, with carbon cores for electrical conductivity and active sites for embedding Zn and H. The p-CDs solely constructed cathode material delivers a superior capacity of 290 mAh g at 0.1 A g and a decent capacity of 103 mAh g at an ultra-high current density of 10 A g, as well as an ultrahigh ion diffusion coefficient of 10 ∼ 10 cm s. The p-CDs assembled ZIBs exhibit a stable long-term cycling, retaining 87.4% of the original capacity after 10 000 cycles. Various characterizations and theoretical calculations prove that the electron-deficient N as the active sites on p-CDs can embed/release Zn and H reversibly.
由于其独特的结构和丰富的性质，碳点（CDs）在电化学领域得到了广泛研究。然而，在已报道的器件中，如电池和超级电容器，CDs一直被用作添加剂来修饰电极或调节电解质，因为它们一直被视为惰性和低容量材料。在此，首次选择邻苯二胺衍生的CDs作为唯一主角来构建水系锌离子电池（ZIBs）的阴极材料。这种CDs（p-CDs）具有特殊的基于吩嗪的π共轭结构，带有用于导电的碳核以及用于嵌入锌和氢的活性位点。仅由p-CDs构建的阴极材料在0.1 A g时具有290 mAh g的优异容量，在10 A g的超高电流密度下具有103 mAh g的可观容量，以及10⁻⁶ ∼ 10⁻⁵ cm² s⁻¹的超高离子扩散系数。由p-CDs组装的ZIBs表现出稳定的长期循环性能，在10000次循环后仍保留原始容量的87.4%。各种表征和理论计算证明，作为p-CDs上活性位点的缺电子氮可以可逆地嵌入/释放锌和氢。
