Li Fengfeng, Ma Hongyun, Sheng Hongwei, Wang Zhaopeng, Qi Yifeng, Wan Daicao, Shao Mingjiao, Yuan Jiao, Li Wenquan, Wang Kairong, Xie Erqing, Lan Wei
School of Physical Science and Technology, Lanzhou University, Lanzhou, Gansu, 730000, P. R. China.
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Research Unit of Peptide Science, Chinese Academy of Medical Sciences 2019RU066, Lanzhou University, Lanzhou, Gansu, 730000, P. R. China.
Small. 2024 Mar;20(13):e2306276. doi: 10.1002/smll.202306276. Epub 2023 Dec 21.
2D transition metal dichalcogenides (TMDs) have garnered significant interest as cathode materials for aqueous zinc-ion batteries (AZIBs) due to their open transport channels and abundant Zn intercalation sites. However, unmodified TMDs exhibit low electrochemical activity and poor kinetics owing to the high binding energy and large hydration radius of divalent Zn. To overcome these limitations, an interlayer engineering strategy is proposed where K is preintercalated into K-MoS nanosheets, which then undergo in situ growth on carbon nanospheres (denoted as K-MoS@C nanoflowers). This strategy stimulates in-plane redox-active sites, expands the interlayer spacing (from 6.16 to 9.42 Å), and induces the formation of abundant MoS 1T-phase. The K-MoS@C cathode demonstrates excellent redox activity and fast kinetics, attributed to the potassium ions acting as a structural "stabilizer" and an electrostatic interaction "shield," accelerating charge transfer, promoting Zn diffusion, and ensuring structural stability. Meanwhile, the carbon nanospheres serve as a 3D conductive network for Zn and enhance the cathode's hydrophilicity. More significantly, the outstanding electrochemical performance of K-MoS@C, along with its superior biocompatibility and degradability of its related components, can enable an implantable energy supply, providing novel opportunities for the application of transient electronics.
二维过渡金属二硫属化物（TMDs）因其开放的传输通道和丰富的锌嵌入位点，作为水系锌离子电池（AZIBs）的阴极材料已引起广泛关注。然而，由于二价锌的高结合能和大水化半径，未改性的TMDs表现出低电化学活性和较差的动力学性能。为克服这些限制，提出了一种层间工程策略，即将钾预嵌入K-MoS纳米片中，然后使其在碳纳米球上原位生长（记为K-MoS@C纳米花）。该策略激发了面内氧化还原活性位点，扩大了层间距（从6.16 Å扩大到9.42 Å），并诱导形成大量的MoS 1T相。K-MoS@C阴极表现出优异的氧化还原活性和快速动力学，这归因于钾离子作为结构“稳定剂”和静电相互作用“屏蔽层”，加速了电荷转移，促进了锌的扩散，并确保了结构稳定性。同时，碳纳米球作为锌的三维导电网络，增强了阴极的亲水性。更重要的是，K-MoS@C出色的电化学性能，以及其相关组分优异的生物相容性和可降解性，能够实现可植入的能量供应，为瞬态电子学的应用提供了新的机遇。
