The Inhibition of Dendrites Using Bipolar Pulse Current for Charge Lithium Electrode

摘要: Introduction The influence of charge model on lithium dendrites formation was investigated by observing surface morphology and measuring electrochemical impedance spectra during process in 1M LiPF6 / EC:DMC (1:1) solution. It found that could be inhibited using bipolar pulse current method. Experimental Pure flat electrode used for testing the change (1:1 weight ratio) DC (0.2mAcm) as models. mode consisted a cathodic 0.2mAcm 0.125s followed an anodic 0.05s continually, carried out with CHI 660 workstation. deposited layer observed situ microscopy method, its also spectra, Potentiostat EG&G Model 273A frequency response analyzer, at 10mH-100kHz 5mV perturbation. Results discussion electrodeposed affected strongly. In case current, dendrite very easy to appear electrode. Fig.1a shows image after been charged 0.16mAhcm under current. were clear. But use net same amount no detected shown Fig.1b. This phenomenon is reasonable, because if some period, it would electrochemically dissolve thoroughly consequent period due much higher took place sharp dendrites. Therefore accumulation happen process. Nyquist plots different stages EC, DMC solution are presented Fig.2a. Each curve presents one semicircle high-meddle region. reflects properties SEI film. resistance Rf capacitance Cf film can calculated based diameter top point semicircle, listed Tab.1. seen drops abruptly increases obviously. huge increase caused when small Fig.2b proves method demonstrates ability inhibit dendrites, which benefit secondary battery. disadvantage this low efficiency limited density. gel polymer electrolyte will discussed also. Acknowledgement work supported National Science Foundation China. References 1. G. Tourillon, F. Garnier, J. Electroanal. Chem., 135 (1982),173. 2. T. Osaka, Momma, Tajima, Y. Matsumoto, Electrochem. Soc., 142 (1995) 1057