Co-reporter:Shuo Zhou, Guixin Wang, Yao Xiao, Qian Li, Dongmin Yang and Kangping Yan
RSC Advances 2016 vol. 6(Issue 68) pp:63378-63389
Publication Date(Web):22 Jun 2016
DOI:10.1039/C6RA08774D
In order to improve safety management, the stress changes of Li(Ni1/3Co1/3Mn1/3)O2 (NMC) cells are real-time monitored using non-destructive strain gauges, and the effects of gauge substrate, temperature and state-of-charge (SOC) have been investigated. The shell exhibits elastic deformation behaviour, and the strain–stress relationship is established. As the temperature increases from 25 to 80 °C, the stress of the NMC cells increases from 0 to 275 MPa, especially greatly at 70 °C and sharply at 80 °C after 18 h. The stress increases from 0 to 9.2 MPa when the potential increases from 2.8 to 4.3 V. However, the value rises from 10 to 55 MPa when the voltage increases from 4.6 to 5.0 V during the over-charge process. An obvious increase of stress appears when the cut-off voltage is below 0.6 V during over-discharge tests. The facile method is significant for non-destructive inspection and emergency management of batteries.
Co-reporter:Qiang Zhao;Kangping Yan;Jixin Yan;Jianzhong Wang
Journal of Applied Polymer Science 2015 Volume 132( Issue 41) pp:
Publication Date(Web):
DOI:10.1002/app.42549
ABSTRACT
Conducting polymers are attractive for potential applications in flexible electronic industries because of their unique advantages. To simplify the process of electrode preparation, porous poly(3,4-ethylenedioxythiophene) (PEDOT) film electrodes without binder and conductive additive were synthesized facilely for flexible supercapacitors via an in situ solution micro polymerization at the surface of a soft etched tunnel aluminum (ETA) template at room temperature. The template was directly used as the current collector of electrodes. The morphologies of the samples and the template were compared using scanning electron microscopy (SEM), and the polymer molecular structure and composition were analyzed with Fourier-transform infrared (FTIR) spectroscopy. Symmetric supercapacitors were assembled with the PEDOT electrodes, Celgard 2300 separator, and 1.0 M LiPF6/EC+DMC+EMC (1 : 1 : 1 in volume) electrolyte. The electrochemical performance was evaluated using different techniques like galvanostatic charging/discharging tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results from different current densities and scanning rates show the supercapacitors have good rate performance. The specific capacitance, energy density, and coulombic efficiency of the PEDOT supercapacitor can reach 69.0 F g−1 (or 103.0 F m−2), 24.0 Wh kg−1, and ∼95% at a current density of 0.2 A g−1, respectively. Furthermore, the PEDOT electrodes exhibit relatively good cycle performance, and the capacitance retention ratio is ∼72% after 1500 cycles. The electrode process was discussed. The results are comparable to that of the reported PEDOT, which indicates the applicability of the novel simple method of solution microreaction at the surface of a soft metal template to directly prepare binder-free flexible electrodes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42549.
Co-reporter:Qiang Zhao, Yan Sun, Guixin Wang, Wei Wu, Chunhui Luo, Kangping Yan, Houfang Lu
Synthetic Metals 2013 Volume 163() pp:42-46
Publication Date(Web):1 January 2013
DOI:10.1016/j.synthmet.2012.12.011
Highly ordered poly(3,4-ethylenedioxythiophene) (PEDOT) tube arrays with hierarchical structure and high aspect ratio were synthesized facilely by an in situ high gravity polymerization in soft Etched Tunnel Aluminum (ETA) metal templates at room temperature. The morphology, microstructure, molecluar structure and interface properties were evaluated by various techniques. The tube length, tube density, and aspect ratio can reach ∼43 μm, ∼107/cm2, and ∼30.7, respectively. The PEDOT arrays synthesized with the feasible method exhibit excellent ultra-hydrophilic properties, and the contact angle of water on the arrays is 1–2° in short spreading time of less than 3s, which is very promising for improving the elcetrochemical performance of PEDOT arrays in aqueous electrolytes.
Co-reporter:Hanchang Kang, Guixin Wang, Heyi Guo, Miao Chen, Chunhui Luo, and Kangping Yan
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 23) pp:7923
Publication Date(Web):May 21, 2012
DOI:10.1021/ie300088p
A facile synthesis route has been developed to prepare LiFePO4/C composites by using Fe–P waste slag from the industrial production of yellow phosphorus. The processes included reclaiming Fe and P in the form of a ferroalloy, preheating the Fe–P with lithium salts, and complementary phosphorus source in air to produce a precursor, and calcining the precursor with glucose in Ar to obtain the products. The reaction process and electrochemical performance were investigated with various techniques. LiFePO4/C with 5.9 wt % carbon exhibits enhanced power capability, low polarization, high reaction activity and reversibility. The discharge capacities are 150, 147, 131, 124, 112, and 93 mAh/g at different current rates of 0.1, 0.2, 0.5, 1, 2, and 5 C, respectively. The recovery rate at 0.1 C is 98.9% after 130 cycles at the given rates. The results are comparable to that of the LiFePO4/C prepared using FePO4 or other Fe salts, which indicates the applicability of the novel simple way put forward in this work to convert industrial waste into energy materials for scaling up based on low cost.
