Highly reversible electrochemical reaction of insoluble 3D nanoporous polyquinoneimines with stable cycle and rate performance
Highly reversible electrochemical reaction of insoluble 3D nanoporous polyquinoneimines with stable cycle and rate performance
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DOI：
10.1016/j.ensm.2019.10.007
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发表时间：
2020-03
影响因子：
20.4
通讯作者：
Huiling Peng;Shengping Wang;Minjun Kim;Jeonghun Kim;Y. Yamauchi;Jingxian Yu;Daoyu Li
中科院分区：
文献类型：
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作者：
Huiling Peng;Shengping Wang;Minjun Kim;Jeonghun Kim;Y. Yamauchi;Jingxian Yu;Daoyu Li
羰基化合物具有比容量大、氧化还原活性中心稳定、效率高、再生能力强等优点，具有作为二次电池正极材料的潜力，但其固有的溶解度和低导电性阻碍了其实际应用。本文通过水热聚合反应合成了三维纳米多孔聚喹啉亚胺（PQ），并将其作为锂离子电池的电极材料进行了研究，以解决其溶解度和电导率问题。纳米玫瑰薄片的各向异性生长形成了PQ的大比表面积（116.95 m2g−1）和丰富的孔隙结构（0.2428 cm3−1），缩短了锂离子的扩散路径，降低了锂的溶解度。1 mg cm−2的PQ电极容量为228（第一次循环，4电子反应时PQ的理论容量为228 mAh g−1）和103（1000次）mAh g−1(50 mA g−1)，在200 mA g−1下，前1000次循环的每循环下降率仅为0.05% （0.077 mAh g−1）。在3 mg cm−2的高负载下，第500次循环的容量为123 mAh g−1，库仑效率为99%。利用密度泛函理论计算了锂化过程中的分子结构，结果表明，坚固的桥键形成并促进了充放电过程的电化学活性。
Carbonyl compounds have potential for use as cathode materials of secondary batteries because of their large specific capacities, stable redox active centers, high efficiencies and ability to regenerate, however their intrinsic solubilities and low electrical conductivities present challenges to hinder their practical utilization. Here, three-dimensional nanoporous polyquinoneimines (PQ) were synthesized by hydrothermal polymerization reactions, and examined as electrode materials in lithium-ion batteries to solve these problems of solubility and electronic conductivity. The large specific surface area (116.95 m2g−1) and abundant pore structure (0.2428 cm3g−1) of the PQ, which were formed by the anisotropic growth of nanosized rose flakes, shortened the lithium-ion diffusion path and reduced lithium solubility. The capacities of the PQ electrodes of 1 mg cm−2were 228 (1st cycle; theoretical capacity of PQ with 4 electron reaction is 228 mAh g−1) and 103 (1000th) mAh g−1at 50 mA g−1, and the declined rate per cycle at 200 mA g−1was only 0.05% (0.077 mAh g−1per cycle) within the first 1000 cycles. The capacity of the 500th cycle with a high load of 3 mg cm−2was 123 mAh g−1, exhibiting a coulombic efficiency of 99%. The molecular structure during lithiation was calculated with density functional theory and showed that the robust bridge bond formed and promoted the electrochemical activity of the charge/discharge process.