Thickness-independent scalable high-performance Li-S batteries with high areal sulfur loading via electron-enriched carbon framework

Abstract

Increasing the energy density of lithium-sulfur batteries necessitates the maximization of their areal capacity, calling for thick electrodes with high sulfur loading and content. However, traditional thick electrodes often lead to sluggish ion transfer kinetics as well as decreased electronic conductivity and mechanical stability, leading to their thickness-dependent electrochemical performance. Here, free-standing and low-tortuosity N, O co-doped wood-like carbon frameworks decorated with carbon nanotubes forest (WLC-CNTs) are synthesized and used as host for enabling scalable high-performance Li-sulfur batteries. EIS-symmetric cell examinations demonstrate that the ionic resistance and charge-transfer resistance per unit electro-active surface area of S@WLC-CNTs do not change with the variation of thickness, allowing the thickness-independent electrochemical performance of Li-S batteries. With a thickness of up to 1200 µm and sulfur loading of 52.4 mg cm−2, the electrode displays a capacity of 692 mAh g−1 after 100 cycles at 0.1 C with a low E/S ratio of 6. Moreover, the WLC-CNTs framework can also be used as a host for lithium to suppress dendrite growth. With these specific lithiophilic and sulfiphilic features, Li-S full cells were assembled and exhibited long cycling stability.

Copolymerization of Sulfur Chains with Vinyl Functionalized Metal−Organic Framework for Accelerating Redox Kinetics in Lithium−Sulfur Batteries

“…After cycling at 1 C for 100 cycles, another new semicircle emerges in the high‐frequency region, related to the resistance of the interface layer ( R I ) caused by the passivation of Li 2 S 2 /Li 2 S (Figure 3f). [ 44 ] After cycling, R ct decreases apparently due to the activation process. Moreover, the CNT@UiO‐66‐V‐S cathode results in lower R ct (13.3 Ω) and R I (4.1 Ω) than the CNT@UiO‐66‐V/S cathode ( R ct = 24.8 Ω, R I = 24.2 Ω).…”

A Silicon Monoxide Lithium-Ion Battery Anode with Ultrahigh Areal Capacity

“…This projection is defined as R ion /3, as derived from a TLM for cylindrical pores. The gradual changes in projection length values for the different electrodes show a decrease in ionic resistance ( R ion ) from 24.8 to 9.6 Ω cm 2 , with increasing pore size in the LHGF scaffold [ 30 ]. Significantly, the R ion values in the holey LHGF/SiO composites are notably lower than that in the non-holey LGF/SiO composites (Fig.…”

“…2d). The reciprocal of the peak frequency corresponds to the relaxation time constant of the electric double-layer, which is an important parameter in characterizing the ion-transfer rate or responsiveness time [29][30][31]. Again, the optimized holey LHGF/SiO composites show a much shorter time constant (1.26 and 1.58 s for LHGF/ SiO-50% and LHGF/SiO-75%, respectively) than that of non-holey composites (2.50 and 3.16 s for LGF/SiO-50% and LGF/SiO-75%, respectively) (Fig.…”

Nano‐Conductive Additive with Low Interfacial Energy Confining the Movement of Lithium Polysulfide Solution Enables Stable Reaction of Sulfur Electrode in Lithium‐Sulfur Batteries

“…[5,6] Thus, the amount of the sulfur cathode continues to decrease, as it dissolves and spreads to all parts of the cell through the uncontrollable and irreversible shuttle effect. [5,6] Previous studies attempted to prevent the shuttle effect by enclosing the sulfur cathode in a specific structure; [7][8][9][10][11] however, lithium polysulfide dissolved in the liquid electrolyte easily passed through the confinement structure and spread throughout the cell. In addition, the corrosive nature of lithium polysulfide accelerated the phenomenon by collapsing the structure for confinement.…”