TY - JOUR AU - Peng, Yufan AU - Chen, Zhen AU - Zhang, Rui AU - Zhou, Wang AU - Gao, Peng AU - Wu, Jianfang AU - Liu, Hui AU - Liu, Jilei AU - Hu, Aiping AU - Chen, Xiaohua PY - 2021/09/13 Y2 - 2024/03/28 TI - Oxygen-Containing Functional Groups Regulating the Carbon/Electrolyte Interfacial Properties Toward Enhanced K+ Storage JF - Nano-Micro Letters JA - Nano-Micro Lett VL - 13 IS - SE - Articles DO - 10.1007/s40820-021-00722-3 UR - https://nmlett.org/index.php/nml/article/view/958 SP - 192 AB - <p>Oxygen-containing functional groups were found to effectively boost the K<sup>+</sup> storage performance of carbonaceous materials, however, the mechanism behind the performance enhancement remains unclear. Herein, we report higher rate capability and better long-term cycle performance employing oxygen-doped graphite oxide (GO) as the anode material for potassium ion batteries (PIBs), compared to the raw graphite. The in situ Raman spectroscopy elucidates the adsorption-intercalation hybrid K<sup>+</sup> storage mechanism, assigning the capacity enhancement to be mainly correlated with reversible K<sup>+</sup> adsorption/desorption at the newly introduced oxygen sites. It is unraveled that the C=O and COOH rather than C-O-C and OH groups contribute to the capacity enhancement. Based on in situ Fourier transform infrared (FT-IR) spectra and in situ electrochemical impedance spectroscopy (EIS), it is found that the oxygen-containing functional groups regulate the components of solid electrolyte interphase (SEI), leading to the formation of highly conductive, intact and robust SEI. Through the systematic investigations, we hereby uncover the K<sup>+</sup> storage mechanism of GO-based PIB, and establish a clear relationship between the types/contents of oxygen functional groups and the regulated composition of SEI.</p><p>Highlights:</p><p>1 Oxygen functional groups improve rate capability as well as long-term cycling stability of graphite oxide.<br>2 The adsorption-intercalation hybrid K<sup>+</sup> storage mechanism of graphite oxide (GO) is elucidated by in situ Raman spectroscopy and systematic electrochemical characterization.<br>3 It is unraveled that the C = O and COOH rather than C-O-C and OH groups contribute to the formation of highly conductive, intact and robust solid electrolyte interphase.</p> ER -