Enhancing kinetics of Li-S batteries by graphene-like N,S-codoped biochar fabricated in NaCl non-aqueous ionic liquid

Abstract

Graphene-like N,S-codoped bio-carbon nanosheets (GNSCS) were prepared by a facile and environment-friendly NaCl non-aqueous ionic liquid route to house sulfur for lithium-sulfur battery. The natural nori powder was calcined at 900°C for 3 h under Ar, in which NaCl non-aqueous ionic liquid can exfoliate carbon aggregates into nanosheets. The structural characterization of GNSCS by a series of techniques demonstrates the graphene-like feature. When evaluated as the matrix for sulfur cathode, GNSCS/S exhibits more prominent cycling stability and rate capability. A discharge capacity of 548 mA h g −1 at a current density of 1.6 A g −1 after 400 cycles was delivered with a capacity fade rate of only 0.13% per cycle and an initial Coulombic efficiency (CE) as high as 99.7%. When increasing the areal sulfur loading up to 3 mg cm −2 , the discharge capacity can still be retained at 647 mA h g −1 after more than 100 cycles with a low capacity degradation of only~0.30% per cycle. The features of N/S dual-doping and the graphene-like structure are propitious to the electron transportation, lithium-ion diffusion and more active sites for chemically adsorbing polysulfides. It is anticipated that other functional biochar carbon can also be attained via the low-cost, sustainable and green method.

Porous honeycomb-like C3N4/rGO composite as host for high performance Li-S batteries

“…The C 1s spectrum of PHCN/rGO in Fig. 3b is deconvoluted into three peaks, in which the typical peak at 284.7 eV is identified as the reference from C-C to calibrate the binding energy of elements [19]. The peaks at 285.7 and 288.7 eV could be attributed to C-O and C-N-C, respectively.…”

“…It has been theoretically and experimentally testified [17,18] that the primary active sites are pyridinic nitrogen, which can interact with LiPSs to accelerate the electrochemical conversion processes and lessen polarization. Pyridinic nitrogen is sp 2 hybridized with lone pair electrons, so it can generate chemical interaction with LiPSs via Li−N to suppress shuttle-effect and improve the performance of Li-S batteries [19,20].…”

Recent progress on biomass‐derived ecomaterials toward advanced rechargeable lithium batteries

“…The randomly distributed pores without interconnected and perforative structure give rise to a long ion diffusion distance or decreased ion transport channel, which lead to high ion migration resistance . Especially in electrodes with high loading, this adverse effect will be amplified owing to the higher response to ion transportation . Therefore, the oriented design of interconnected architecture with low tortuosity electrode should be strongly encouraged.…”

“…89,[102][103][104][105] Especially in electrodes with high loading, this adverse effect will be amplified owing to the higher response to ion transportation. 106,107 Therefore, the oriented design of interconnected architecture with low tortuosity electrode should be strongly encouraged. Enlightened by well-aligned channel structure within natural wood for water and ion transport, Hu and coworkers developed a 3D aligned porous carbon matrix derived from natural wood to accommodate cathode electrocatalysts in Li-O 2 batteries ( Figure 5A).…”

A Promising Hard Carbon−Soft Carbon Composite Anode with Boosting Sodium Storage Performance

“…However, the limited and unevenly distributed lithium resources make LIBs hardly afford to the increasing demand pressure. [4,5] Hence, it is urgent to explore the next generation of batteries for largescale use. Due to the global abundance and more affordability of sodium, sodium-ion batteries (SIBs) with analogue energy storage mechanism and electrochemical operation to LIBs are deemed to be a prospective alternative.…”