Developing a high sulfur (S)-loading cathode with high capacity utilization and long term cyclability is a key challenge for commercial implementation of Li-S battery technology. To overcome this challenge, we propose a solid-phase conversion sulfur cathode by using an edible fungus slag-derived porous carbon (C_FS) as sulfur host to fabricate the S/C_FS composite and meanwhile, utilizing the vinyl carbonate (VC) as co-solvent of the ether-based electrolyte to in-situ form a protective layer on the S/C_FS composite surface through its nucleophilic reaction with the freshly generated lithium polysulfides (LiPSs) at the very beginning of initial discharge, thus isolating the interior sulfur from the outer electrolyte and inhibiting the further generation of soluble LiPSs. Benefitting from the ultrahigh specific surface area of > 3,000 m²·g⁻¹, ideal pore size of < 4 nm, and large pore volume of > 2.0 cm³·g⁻¹ of the C_FS host matrix, the S/C_FS cathode even with a high S-loading of 80 wt.% (based on the weight of S/C_FS composite) can still operate in a solid-phase conversion manner in the VC-ether co-solvent electrolyte to exhibit a high reversible capacity of 1,557 mAh·g⁻¹, a high rate capability with 50% remaining capacity at 2 A·g⁻¹ and a high cycling efficiency of 99.9% over 500 cycles. The results presented in this work suggest that a combined action of solid-phase conversion electrochemistry and nanoarchitectured host structure may provide a new path for the design and development of practical lithium-sulfur batteries.

Fabricating three-dimensional (3D) composite lithium anodes via thermal infusion effectively addresses uncontrollable Li deposition and large volume changes. However, potential risks due to the long wetting time and high melting point remain a critical yet unconsidered issue. Herein, we report a stable 3D composite Li anode by infusing molten Li into a 3D scaffold within 3 s at 220 °C. The key-enabling technique is the growth of a lithiophilic Mg-Al double oxide (LDO) nanosheet array layer on the scaffold. The in-situ formed lithiophilic alloy, combined with the capillary forces from the nanosheet arrays, enabled the transient infiltration of molten Li. In addition, the formed high ionic-conductivity Li phase can help construct a robust solid electrolyte interphase (SEI), stabilize the Li anode/electrolyte interface, and guide uniform Li deposition. The 3D composite anode exhibited a long cycling life of 1,000 h under a current density of 1 mA·cm⁻² and over 1,600 h under a current density of 2 mA·cm⁻² with a high areal capacity of 4 mAh·cm⁻² in Li/Li symmetric cells. The 3D composite anodes paired with high areal capacity LiFePO₄ (LFP) and S cathodes demonstrate its practical application feasibility.

Hard carbon derived from biomass is regarded as a promising anode material for sodium-ion batteries (SIBs) because of its low operating potential, high capacity, resource availability, and low cost. However, scientific and technological challenges still exist to prepare hard carbon with a high initial Coulombic efficiency (ICE), an excellent rate capability, and good cycling stability. In this work, we report a self-supported hard carbon electrode from fungus-pretreated basswood with an improved graphitization degree and a low tortuosity. Compared with the hard carbon derived from basswood, the hard carbon electrode from fungus-pretreated basswood has an improved rate capability of 242.3 mAh·g⁻¹ at 200 mA·g⁻¹and cycling stability with 93.9% of its capacity retention after 200 cycles at 40 mA·g⁻¹, as well as the increased ICE from 84.3% to 88.2%. Additionally, ex-situ X-ray diffraction indicates that Na⁺ adsorption caused the sloping capacity, whereas Na⁺ intercalation between interlayer spacing corresponded to the low potential plateau capacity. This work provides a new perspective for the preparation of high-performance hard carbon and gains the in-depth understanding of Na storage mechanism.

Silicon has attracted much attention as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and rich resource abundance. However, the practical battery use of Si is challenged by its low conductivity and drastic volume variation during the Li uptake/release process. Tremendous efforts have been made on shrinking the particle size of Si into nanoscale so that the volume variation could be accommodated. However, the bare nano-Si material would still pulverize upon (de)lithiation. Moreover, it shows an excessive surface area to invite unlimited growth of solid electrolyte interface that hinders the transportation of charge carriers, and an increased interparticle resistance. As a result, the Si nanoparticles gradually lose their electrical contact during the cycling process, which accounts for poor thermodynamic stability and sluggish kinetics of the anode reaction versus Li. To address these problems and improve the Li storage performance of nano-Si anode, proper structural design should be applied on the Si anode. In this perspective, we will briefly review some strategies for improving the electrochemistry versus Li of nano-Si materials and their derivatives, and show opinions on the optimal design of nanostructured Si anode for advanced LIBs.