Behavior of Secondary Lithium and Aluminum‐Lithium Electrodes in Propylene Carbonate

Abstract

The improvement of the lithium cycling efficiency obtained by substituting an aluminum substrate for a lithium substrate is explained by means of morphological and kinetic studies of the electrodes in the molar solution LiClO4‐normalpropylene carbonate . SEM observations show that the insertion rate of the lithium deposit into aluminum can be sufficiently high so as to avoid dendritic growth; ESCA analysis reveals that propylene carbonate leads to a chemical formation of a polymeric membrane on the electrodes, which is less important on the aluminum than on the lithium substrate. Electrochemical impedance measurements associated with polarization curve data point out that most of the surface is active, giving rise to an exchange current density of about 17 mA/cm2; these studies also demonstrate that diffusion processes in the passivating layer and in the bulk of the electrode are responsible for the limited lithium cycling performances with the aluminum substrate.

Three‐dimensionai temperature and current distribution in a battery module

“…To determine an upper bound on ALl.L,+, note the highest exchange current density reported for the Li-Lif at 298 K is 31.6 mA/cm2 (Verbrugge and Koch, 19941, yielding AL,.=,+ = 54.9 kA/cm2. In general, the reported exchange current densities are typically about an order of rnagnitude lower than this (Butler et al, 1969;Meibuhr, 1970Meibuhr, , 1971JornC and Tobias, 1974;Epelboin et al, 1980;Scarr, 1986;Morzilli et al, 19871, and a value of A = 5.49 kA/cm2 was used for the base case. Various sensitivities are done in the results and discussion section that elucidate the importance of this parameter.…”

Factors That Control the Formation of Dendrites and Other Morphologies on Lithium Metal Anodes

“…However, many fundamental challenges must be addressed before lithium electrodes can be deployed in practical devices (Aurbach et al, 2000(Aurbach et al, , 2002. One of the main challenges is the nucleation and growth of protrusions during battery charging (Selim and Bro, 1974;Besenhard and Eichinger, 1976;Epelboin, 2006), which limits the battery lifetime and compromises safety (Yamaki et al, 1998;Aurbach et al, 2002). These protrusions are often referred to as "lithium dendrites."…”

Liquid cell transmission electron microscopy observation of lithium metal growth and dissolution: Root growth, dead lithium and lithium flotsams

“…7 An initially smooth Li metal anode is prone to surface morphological instabilities in electrochemical cycling, forming extended protrusions that can cause not only dramatic loss of reversible capacity, but also penetration of the separator, short-circuiting, and in the worst cases heating and catastrophic burning. 8 Numerous researches have been conducted in the last 40 years to understand the mechanisms and morphologies of Li metal growth, both experimentally [9][10][11][12][13][14][15] and theoretically, 6,[16][17][18][19] and methods to suppress the dendrite formation have also been proposed. 2,[20][21][22][23][24][25] Generally, the morphology of the electrochemically deposited solid is affected by the current density and overpotential, [26][27][28] and various qualitative theories have been developed to explain the growth mechanism.…”