Stable and ultrafast lithium storage for LiFePO4/C nanocomposites enabled by instantaneously carbonized acetylenic carbon-rich polymer
The low electronic conductivity and poor Li + diffusion coefficient of conventional LiFePO 4 (LFP) materials severely impede its high-rate applications for lithium-ion batteries (LIBs). To break these limits, one novel poly(1,3-diethynylbenzene) (PAB) acetylenic carbon-rich polymer with extremely high-carbon content (96.75 wt%) and good solubility has been prepared by an oxidative coupling reaction. One definite advantage is that this carbon-rich PAB polymer will release, upon pyrolysis , very low amounts of gas, forming therefore uniform and dense highly conductive carbon network. Besides, the specific resistivity of continuous PAB-C layer can be as low as ∼0.01 Ω cm, which can effectively improve electrical conductivity and maintain mechanical integrity of LFP cathode. As a result, the prepared LFP@PAB-C nanocomposites with approximately 3.8 wt% carbon content and 2.5 nm carbon layer exhibit an excellent high-rate capability, e.g. even at a considerable discharge rate of 50 C, while the capacity can still be remained at 129.6 mA h g −1 . Moreover, the LFP@PAB-C nanocomposites also reveal a remarkable cycling stability with as high as 100.6% capacity retention at 20 C over 1000 cycles. This kind of LFP@PAB-C composite was demonstrated to be an ideal cathode material for high-power LIBs.
危险品化学品经营许可证（带存储）