韩国科技院《Carbon》：沥青衍生多孔碳的新方法，用于高效钾离子电池

图1. The XRD patterns (a), TGA curves (b), and the structural schematics (c) of fluorinated pitches.

图2. The schematics for preparation of porous carbon with fluorination-defluorination swing reaction (a), XRD patterns (b), Raman spectra (c), N2 adsorption-desorption isotherms (d), pore size distribution (e), XPS F1s of ANF30C1000 (f), ANF60C1000 (g), ARF30C1000 (h), and ARF60C1000 (i).

图3. The SEM images of ANF30C1000 (a), ANF60C1000 (b), ARF30C1000 (c), and ARF60C1000 (d), TEM images of ANF30C1000 (e), ANF60C1000 (f), ARF30C1000 (g), and ARF60C1000 (h).

图4、The formation mechanisms (a) of porous carbons from FSR, and the rate capabilities (b), cycle stabilities (c), GITT profiles (d), diffusion coefficient during potassiation (e) and de-potassiation (f) of FSR treated porous carbons based KIB cells.

图5. The XRD patterns (a), Raman spectra (b), N2 adsorption-desorption isotherms (c) of AR based porous carbons with FSR; their reaction mechanisms (d), galvanostatic charge-discharge curves (e), rate and cycle performances (f).

图6. CV curves of ARF30C1000 at various scan rates (a), capacitive contribution of ARF30C1000 at scan rate of 0.2 mV s-1 (b), capacitive and diffusion contribution with increasing scan rates of ARF30C1000 (c), in situ Raman spectra (left) at first cycle and corresponding charge-discharge curve of ARF30C1000 (d), log(i) vs. log(v) plots for ARF30C800, 1000, and 1500 (e), and the variation of ID/IG value and Raman shift of G band of ARF30C1000 vs. potential.

本研究提出了一种通过氟化-脱氟摆动反应合成沥青基多孔碳材料的创新方法，并探讨了这些材料作为 KIB 负极材料的潜力。通过对各向同性沥青和中间相沥青进行氟化和随后的脱氟摆动反应，我们成功制备出了具有不同结构和电化学性能的多孔碳。值得注意的是，由氟化 30 分钟的间相沥青制备的 ARF30C1000 表现出卓越的性能，在电流密度为 50 mA g-1 时，比放电容量达到 265.5 mAh g-1。这种优异的性能归功于多孔碳材料的高表面积和增强的结晶度促进了钾插入和吸附的协同效应。此外，我们的研究还发现，脱氟过程不仅能通过产生缺陷来推动孔隙的生成，还能加速聚合，从而改善材料的整体结构和功能。进一步的实验表明，随着脱氟温度的升高，孔隙的产生会一直持续到氟完全脱除，随后孔隙会因缺陷愈合而闭合。这些发现强调了脱氟法作为生产高性能沥青基多孔碳的一种可行方法的潜力，并为未来储能技术的进步铺平了道路。