A Sulfur–Limonene‐Based Electrode for Lithium–Sulfur Batteries: High‐Performance by Self‐Protection

Abstract

The lithium-sulfur battery is considered as one of the most promising energy storage systems and has received enormous attentions due to its high energy density and low cost. However, polysulfide dissolution and the resulting shuttle effects hinder its practical application unless very costly solutions are considered. Herein, a sulfur-rich polymer termed sulfur-limonene polysulfide is proposed as powerful electroactive material that uniquely combines decisive advantages and leads out of this dilemma. It is amenable to a large-scale synthesis by the abundant, inexpensive, and environmentally benign raw materials sulfur and limonene (from orange and lemon peels). Moreover, owing to self-protection and confinement of lithium sulfide and sulfur, detrimental dissolution and shuttle effects are successfully avoided. The sulfur-limonene-based electrodes (without elaborate synthesis or surface modification) exhibit excellent electrochemical performances characterized by high discharge capacities (≈1000 mA h g at C/2) and remarkable cycle stability (average fading rate as low as 0.008% per cycle during 300 cycles).

Recent Advances in Applying Vulcanization/Inverse Vulcanization Methods to Achieve High‐Performance Sulfur‐Containing Polymer Cathode Materials for Li–S Batteries

“…As well as these examples of S‐DIB polymer composites, other sulfur polymer/carbon nanomaterial composites such as the composites of poly(S‐r‐Ca) (90 wt% sulfur loading, denoted as S90) with reduced graphene oxide (rGO) and multiwall carbon nanotubes (MWCNT), S90/rGO (Figure g), and S90/MWCNT; graphene‐supported highly cross‐linked S‐TTCA copolymer [cp(S‐TTCA)] nanocomposite, cp(S‐TTCA)@rGO (Figure h). The composites of sulfur–limonene polysulfide (SLP) with graphene and carbon spheres (CS), graphene‐SLP, and CS‐SLP have been developed. All of these composites showed enhanced electrochemical performance compared with that of their bulk polymers.…”

“…On one hand, some polymer binders showed excellent properties in reducing Li–S cell impedance, actively regulating ion transport and enabling strongly anchoring polysulfides, and some conductive polymers have been used as binders in some inorganic electrodes . By selecting some special current collectors, some sulfur‐containing polymers such as rubber products and sulfur–limonene polysulfide can act as both active material and binder at the same time to form a binder‐free and conductive agent‐free electrode for use as the cathode of Li–S batteries. On the other hand, sulfur copolymers can be simultaneously endowed with high sulfur content and high electrical conductivity along with controllable morphology.…”

“…as binders in some inorganic electrodes. [132] By selecting some special current collectors, some sulfur-containing polymers such as rubber products [80] and sulfur-limonene polysulfide [89] can act as both active material and binder at the same time to form a binder-free and conductive agent-free electrode for use as the cathode of Li-S batteries. On the other hand, sulfur copolymers can be simultaneously endowed with high sulfur content and high electrical conductivity along with controllable morphology.…”

A Stable Quasi‐Solid‐State Sodium–Sulfur Battery

“…[12] During the anodic scan, only ar epeatable peak at around 2.1 Vassigned to the reversible transformation from short-chain sodium sulfides to long-chain polysulfides appears over all cycles. [13] Figure 3a shows the Fourier transform infrared spectroscopy (FTIR) spectra of the PETEA monomer,T HEICTA monomer and the polymer matrix of (PETEA-THEICTA)based GPE obtained by removing LE from the GPE. [13] Figure 3a shows the Fourier transform infrared spectroscopy (FTIR) spectra of the PETEA monomer,T HEICTA monomer and the polymer matrix of (PETEA-THEICTA)based GPE obtained by removing LE from the GPE.…”

“…[3] It is excepted that the embedding of polymer matrix in the poly(S-PETEA) not only acts as an intrinsic binder,b ut also chemically confines Na polysulfides during cycling ( Figure S7). [13] Figure 3a shows the Fourier transform infrared spectroscopy (FTIR) spectra of the PETEA monomer,T HEICTA monomer and the polymer matrix of (PETEA-THEICTA)based GPE obtained by removing LE from the GPE. Peaks at 1168 cm À1 (CÀO, symmetrical stretching), 1724 cm À1 (C=O stretching) and 1684 cm À1 (isocyanurate ring stretching) appear in the spectra of monomers.I ti ss een that the peak at approximately 1637 cm À1 assigned to the stretching vibration of C = Cbonds nearly disappears in the spectrum of GPE matrix.…”