Electrochemical Investigation of All-Solid-State Lithium Batteries with a High Capacity Sulfur-Based Electrode

Abstract

Polyacrylonitrile (PAN) was combined with elemental sulfur (S) using a facile procedure that produces a highly conductive and high capacity active material, PAN-S. PAN-S is shown in this work to be capable of extremely high energy density and good cycle stability in all-solid-state lithium batteries utilizing a sulfide based solid electrolyte. All-solid-state batteries employing PAN-S as active material maintained over 605 mAh g −1 for 50 cycles, and composite active materials containing less sulfur resulted in lower overall specific capacity but excellent cycle stability with less than 1% loss over 50 cycles. A high energy density of over 700 Wh kg −1 was achieved for all-solid-state lithium battery electrodes incorporating 57% active material into the cathode composite.

High Capacity Sulfurized Alcohol Composite Positive Electrode Materials Applicable for Lithium Sulfur Batteries

“…This is consistent with the results of the elemental contents listed in Table I. Rather weak, broad peaks at 380 and 470 cm −1 , which were also observed in the SPAN sample, were assigned to S-S deformation and C-S stretching vibrations, 13,14 respectively, indicating the presence of S-S and C-S bonds in the SAC samples. These chemical bonds would be formed by the refluxing reaction of elemental sulfur and primary alcohol.…”

“…1a, which enables the Li + migration path to the particle surface shortened to improve the utilization of the active material. Indeed, the SAC (n = 9) sample cells with 33% AB content showed comparable rate capability to that of the previously reported SPAN sample cells, 13,14 as shown in Fig. 6c, but the SAC (n = 9) sample cells with reduced AB content (ca.…”

“…11,13,16 Figure 1a shows the typical high resolution TEM micrographs for the SAC (n = 9) sample. The sample powder consisted of the agglomerated particles with the size of several tens nanometers, and any lattice fringes originated from the long-range ordering of the constituent atoms were not observed even in the most enlarged scale, indicating that the sample was in an amorphous state.…”

“…We also prepared SPAN sample after the procedure reported previously. 13 The phase purity of the sample was checked by X-ray diffraction (XRD) measurements (Rotaflex RU-200B/RINT, Rigaku, Japan) using monochromatic Cu Kα radiation within the 2θ range of 10-125…”

“…[11][12][13][14][15][16] In this organosulfur material (sulfurized PAN, referred to as SPAN), sulfur is covalently bound to the polymer chain or interconnects the PAN network as a cross-linking agent. [11][12][13][14][15][16] Such sulfur-carbon framework effectively suppressed the dissolution of polysulfides into the electrolyte, resulting in the excellent cycle stability of the cells. Although the efficient sulfur-carbon frameworks have been developed, there still remain challenges for exploring other organosulfur materials, for example, with higher sulfur contents, using inexpensive and non-toxic reagents; the typical SPAN showed the sulfur content of 50-55 wt%, resulting in the specific capacity of ca.…”