Physical and Chemical Characteristics of Hermetically Sealed High Rate Li / SOCl2 C‐Cells

Abstract

Pressure‐temperature‐voltage relationships in hermetically sealed high rate normalLi/SOCl2 cells have been studied using specially instrumented C‐size cells. The cells generated considerably lower pressures than those expected on the basis of established discharge reactions. This is believed to be due to the SO2 generated being complexed by LiAlCl4 and/or absorbed by the carbon cathode. Li‐limited cells produced lower internal temperatures and pressures towards the end of discharge and during voltage reversal than cathode‐limited cells. In high rate discharge involving >10 mA/cm2, Co‐TAA‐catalyzed cathode cells exhibited higher capacities and lower IR heating than uncatalyzed cells. Li‐limited Co‐TAA catalyzed cathode cells appear to be a desirable design for high rate applications.

High-Capacity Rechargeable Li/Cl2 Batteries with Graphite Positive Electrodes

“…From XPS analysis, we have determined that the actual concentration of LiFSI dissolved was ∼0.047 M (Figure S3, also see Methods). The first discharge to 2 V (Figure d) was due to the SOCl 2 reduction to S, SO 2 and with LiCl deposition on the positive electrode, delivering a voltage/capacity of ∼3.18 V/∼1391 mAh g –1 and ∼3.37 V/∼1911 mAh g –1 for the Li/DGr and Li/DGr_ac cells, respectively (Figure d). ,− The improved first discharge capacity of DGr_ac over DGr was attributed to a ∼42.9% increase in the surface area (13.11 to 18.73 m 2 g –1 ) and a ∼40.0% increase in the pore volume (from 0.05 to 0.07 cm 3 g –1 ) (Table S1, Figure S4), afforded by high-temperature CO 2 activation that etched graphite at the edges and in-plane defects (Figures a and S1). The larger surface area and pore volume provided more available sites to host the LiCl deposition accompanied by a higher first discharge capacity. , In addition, a noticeable ∼0.19 V increase in the first discharge voltage from ∼3.18 V in the Li/DGr battery to ∼3.37 V in the Li/DGr_ac battery was observed (Figure d), suggesting a possible catalytic effect for the formation and deposition of LiCl on DGr_ac on defects with oxygen-containing functional groups resulted from CO 2 etching. , …”

Shedding Light on Rechargeable Na/Cl2 Battery

“…We first discharged the battery to 2 V at a current density of 50 mA g -1 , through which SOCl2 was reduced to form SO2, S and NaCl, with the latter deposited on the aCNS electrode until passivation 1,[16][17][18] . After the first discharge, the battery was set to cycle at a specific capacity of 1200 mAh g -1 with 100 mA g -1 current (Fig.…”

A Thermal Analysis of a Spirally Wound Battery Using a Simple Mathematical Model

“…kk'x --Ox 1/1" + kk'y ~y ny = 0 [6] or a convection boundary condition aT aT -hk.x --nx -kk.y ~y nu = h(Tw -T^) [7] ay is used. In Eq.…”

“…First, this data is for a cell having porous cathodes containing 5 weight percent (w/o) dibenzotetraazaannulene complex of cobalt (Co-TAA). These catalyzed cells exhibit different discharge behavior from uncatalyzed cells (6), and the heat generation rate, as predicted using Eq. [5] and the thermoneutral potential listed in Table II, used in the model may not be appropriate.…”

“…One-dimensional approximations to the two-dimensional analysis will be investigated for comparison purposes. Predictions from a one-dimensional model for a C-size cell are compared with experimental data (6) to learn more about the thermal behavior of Li/SOC12 cells. Finally, hypothetical thermal runaway situations are simulated using the two-dimensional model and a one-dimensional approximation in order to determine if the spiral design offers any thermal advantage under such conditions.…”