Investigation on Cycling and Calendar Aging Processes of 3.4 Ah Lithium-Sulfur Pouch Cells

Abstract

Much attention has been paid to rechargeable lithium-sulfur batteries (Li–SBs) due to their high theoretical specific capacity, high theoretical energy density, and affordable cost. However, their rapid c fading capacity has been one of the key defects in their commercialization. It is believed that sulfuric cathode degradation is driven mainly by passivation of the cathode surface by Li2S at discharge, polysulfide shuttle (reducing the amount of active sulfur at the cathode, passivation of anode surface), and volume changes in the sulfuric cathode. These degradation mechanisms are significant during cycling, and the polysulfide shuttle is strongly present during storage at a high state-of-charge (SOC). Thus, storage at 50% SOC is used to evaluate the effect of the remaining degradation processes on the cell’s performance. In this work, unlike most of the other previous observations that were performed at small-scale cells (coin cells), 3.4 Ah pouch Li–SBs were tested using cycling and calendar aging protocols, and their performance indicators were analyzed. As expected, the fade capacity of the cycling aging cells was greater than that of the calendar aging cells. Additionally, the measurements for the calendar aging cells indicate that, contrary to the expectation of stopping the solubility of long-chain polysulfides and not attending the shuttle effect, these phenomena occur continuously under open-circuit conditions.

A Promising Approach towards the Commercialization of Lithium Sulfur Batteries: Prelithiated Graphene

“…The electrochemical performance of lithium and Li‐CM anodes was evaluated through cyclic voltammetry (CV) measurements conducted at a scan rate of 0.1 mV/s. The CV curve for the cathode in Figure 6a exhibits the characteristic two pairs of cathodic/anodic peaks, corresponding to the reversible redox reaction between S and Li 2 S occurring in two steps [40–43] . The findings demonstrate that the lithium metal anode outperforms the Li‐CMs in terms of current output.…”

Investigation of the temperature and DOD effect on the performance-degradation behavior of lithium–sulfur pouch cells during calendar aging

“…The majority of aging studies focus on small-scale testing and one research presents cycling aging of 19 Ah Li-S pouch cell [52]. Less attention is paid to self-discharge and calendar aging, the publications mostly deal with short-term self-discharge studies [44,53,54], or cells stored at one condition [55]. The self-discharge behavior of Li-S batteries was studied using polymer electrolyte and liquid electrolyte on a small scale [56,57] and on Li-S pouch cells for a short time period [58].…”

Investigation of the Effect of Temperature on Lithium‐Sulfur Cell Cycle Life Performance Using System Identification and X‐Ray Tomography

“…Although the electrochemical models can help a lot to better understand the ageing mechanisms of different batteries, such high‐fidelity models are not necessarily helpful for real‐time applications due to their additional computational cost. Example studies of the Li−S BMS are presented in previous reports, [27,28] where an experimental methodology is used to investigate Li−S cell ageing. One of the restrictions in those previous studies is related to the cycling charge/discharge current profiles, which are not based on a realistic duty cycle.…”

“…In the present study however, the cells are subjected to a more realistic degradation scenario, which is an EV driving cycle test. Furthermore, the Li−S cells which had been used previously [27,28] were of a lower capacity type (i. e., 3.4 Ah) whereas in this study, a new high capacity (i. e., 19 Ah) Li−S cell is investigated. For example, the impact of ageing on cell's capacity and internal resistance are studied [28] .…”