Dendritic Li deposition, an unstable solid-electrolyte interphase (SEI), and a nearly infinite relative volume change during cycling are three major obstacles to the practical application of Li metal batteries. Herein, we introduce a compressible and elastic reduced graphene oxide sponge (rGO-S) to simultaneously eliminate Li dendrite growth, stabilize the SEI, and accommodate the volume change. The volume change is contained by compressing and expanding the rGO-S anode, which effectively releases the Li plating-induced stress during cycling. The smooth and dense Li metal is deposited on rGO-S without dendrites, which preserves the SEI, reduces consumption of the electrolyte, and prevents the formation of Li debris. The half-cells employing rGO-S show a steady and high Coulombic efficiency. The Li@rGO-S symmetric cells demonstrate excellent cycling stability over 1200 cycles with a low overpotential. When paired with LiFePO4 (LFP), the Li@rGO-S||LFP full cells exhibit a high specific capacity (150.3 mAh g-1 at 1C), superior rate performance, and good capacity retention.

The substitution of conventional graphite with Li metal as an anode material has garnered significant interest due to its exceptionally high theoretical energy density. However, the direct application of Li metal as an anode in batteries faces formidable challenges, including dendrite growth and interphase instability. Herein, a high-performance composite anode (LZ-rGO) that integrates a reduced graphene oxide (rGO) scaffold with lithiophilic Li-Zn alloy nanoparticles is presented. The Li-Zn seeds embedded in the structure lower the initial nucleation barrier and facilitate uniform Li deposition. Furthermore, the rGO scaffold, possessing a large specific surface area, enables the LZ-rGO anode to significantly reduce voltage hysteresis and prevents the deactivation of metallic Li during the plating/stripping processes. As a result, the symmetric cell demonstrates stability over 1200 h at a current density of 1 mA cm-2, with negligible voltage fluctuation. When paired with a LiFePO4 cathode, the full cell achieves stable cycling for 1000 cycles with a high-capacity retention, demonstrating exceptional interface stability and cycling efficiency.

Lithium metal has been recognized as a promising anode candidate for next-generation rechargeable batteries due to its low chemical potential and high specific capacity, yet it is plagued by poor cycling stability due to the uncontrolled growth of Li dendrites. Herein, we fabricate SiO2 nanoparticle pillared MXene (Ti3C2Tx) composite films through a facile vacuum-assisted self-assembly method, which can serve as stable and dendrite-free Li metal anodes. The lithiophilic MXene can foster Li nucleation and growth, while the insulating SiO2 nanoparticles acting as lithiophilic seeds further induce uniform Li nucleation and deposition. The SiO2 nanoparticles also serve as supporting pillars between the MXene layers which facilitate Li ion transportation and minimize volume shrinkage during delithiation. Li is preferentially deposited into the interior of the MXene/SiO2 composite film and the flat, dendrite-free, granular Li layer is formed on its surface. Under the synergistic effects of MXene and SiO2, the MXene/SiO2/Li anodes demonstrate low Li deposition overpotential, small voltage hysteresis, high coulombic efficiency and low charge transfer resistance. When coupled with an LiFePO4 cathode, the full cell shows stable voltage polarization and good cyclability. Under fast charging, it retains high-rate capacity and remains stable for 320 cycles at 3C with negligible capacity decay, demonstrating its excellent rate performance.

With NaBH4 as the assistant reductant, small and highly dispersed Pt nanoparticles are formed on E-MoS2 nanosheets which provide abundant catalytically active sites and exhibit excellent hydrogen evolution reaction (HER) performance.

Two-dimensional transition-metal dichalcogenides are affordable alternatives to noble metal catalysts for hydrogen evolution reaction (HER). Here, we report a facile one-step solvothermal method to synthesize the 1T MoS2 hierarchical nanosphere (NSP) that can function as an efficient and stable electrocatalyst for HER using an environment-friendly solvent without the assistance of a template or additive. The reaction solvent is found to play a vital role in regulating the morphology and phase of the resultant MoS2. A haystack of 2H MoS2 nanosheets is obtained when water is used as the solvent, and the 1T MoS2 NSP is attained when ethanol is used. The 1T MoS2 NSP has a three-dimensional hierarchical structure and good conductivity, which lead to the excellent electrocatalytic HER performance in an acid solution with its overpotential lower than the reported MoS2-based electrocatalysts. It also demonstrates exceptional electrochemical stability, showing little variation in overpotential for 5000 reaction cycles.