Solid-state lithium metal batteries (SSLMBs) are promising energy storage devices by employing lithium metal anodes and solid-state electrolytes (SSEs) to offer high energy density and high safety. However, their efficiency is limited by Li metal/SSE interface barriers, including insufficient contact area and chemical/electrochemical incompatibility. Herein, a strategy to effectively improve the adhesiveness of Li metal to garnet-type SSE is proposed by adding only a few two-dimensional boron nitride nanosheets (BNNS) (5 wt %) into Li metal by triggering the transition from point contact to complete adhesion between Li metal and ceramic SSE. The interface between the Li-BNNS composite anode and the garnet exhibits a low interfacial resistance of 9 Ω cm2, which is significantly lower than that of bare Li/garnet interface (560 Ω cm2). Furthermore, the enhanced contact and the additional BNNS in the interface act synergistically to offer a high critical current density of 1.5 mA/cm2 and a stable electrochemical plating/striping over 380 h. Moreover, the full cell paired with the Li-BNNS composite anode and the LiFePO4 cathode shows stable cycling performance at room temperature. Our results introduce an appealing composite strategy with two-dimensional materials to overcome the interface challenges, which provide more opportunities for the development of SSLMBs.

Current knowledge on Na metal anode has been limited on its room-temperature or high-temperature (molten Na-S system) performances. However, the properties regarding to its low-temperature and fast-charging performances are rarely...

Solar cells based on hybrid organic-inorganic metal halide perovskites are being developed to achieve high efficiency and stability. However, inevitably, there are defects in perovskite films, leading to poor device performance. Here, we employ an additive-engineering strategy to modify the grain boundary (GB) defects and crystal lattice defects by introducing a strong electron acceptor of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) into perovskite functional layer. Importantly, it has been found that F4TCNQ is filled in GBs and there is a significant reduction of metallic lead defects and iodide vacancies in the perovskite crystal lattice. The bulk heterojunction perovskite-F4TCNQ film exhibits superior electronic quality with improved charge separation and transfer, enhanced and balanced charge mobility, as well as suppressed recombination. As a result, the F4TCNQ doped perovskite device shows excellent device performance, especially the reproducible high fill factor (up to 80%) and negligible hysteresis effect.

Solid-state Li metal batteries (SSLMBs) have emerged as an important energy storage technology that offers the possibility of both high energy density and safety by combining a Li metal anode...

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High-efficiency organic solar cells (OSCs) can be produced through optimization of component molecular design, coupled with interfacial engineering and control of active layer morphology. However, vertical stratification of the bulk-heterojunction (BHJ), a spontaneous activity that occurs during the drying process, remains an intricate problem yet to be solved. Routes toward regulating the vertical separation profile and evaluating the effects on the final device should be explored to further enhance the performance of OSCs. Herein, we establish a connection between the material surface energy, absorption, and vertical stratification, which can then be linked to photovoltaic conversion characteristics. Through assessing the performance of temporary, artificial vertically stratified layers created by the sequential casting of the individual components to form a multilayered structure, optimal vertical stratification can be achieved. Adjusting the surface energy offset between the substrate results in donor and acceptor stabilization of that stratified layer. Further, a trade-off between the photocurrent generated in the visible region and the amount of donor or acceptor in close proximity to the electrode was observed. Modification of the substrate surface energy was achieved using self-assembled small molecules (SASM), which, in turn, directly impacted the polymer donor to acceptor ratio at the interface. Using three different donor polymers in conjunction with two alternative acceptors in an inverted organic solar cell architecture, the concentration of polymer donor molecules at the ITO (indium tin oxide)/BHJ interface could be increased relative to the acceptor. Appropriate selection of SASM facilitated a synchronized enhancement in external quantum efficiency and power conversion efficiencies over 10.5%.

High entropy materials, a horizon-broadening class of materials with complex stoichiometry, have gained significant interest recently. The ideal regulation and the attractive synergy effect make high entropy materials promising candidates for energy storage devices. In this Perspective, we present a survey of high entropy materials as anodes, cathodes, catalysts, and solid-state electrolytes in rechargeable batteries. The entropy-stabilized rock-salt-type Co0.2Cu0.2Mg0.2Ni0.2Zn0.2O is highlighted due to its multiple functions. Suggestions on future perspectives of HEM as an important role in next-generation batteries are given.

The solid-electrolyte interphase (SEI) is known to dictate the performance of a Li metal anode, where its inorganic compositions are primarily responsible for Li + conduction, electron insulation, and thus a compact Li deposition. In this work, we formulate a nonflammable and highly fluorinated electrolyte recipe for a highly reversible Li metal anode. By concurrently incorporating the F-donating anions and solvent molecules into the primary Li + solvation sheath, an inorganic-rich SEI with high F content is produced. The low solvation energy of the tailored solvation sheath further reduces the barrier for Li + desolvation, contributing to accelerated kinetics under fast charging and subzero conditions. Consequently, dramatic improvements in the Li deposition morphology, Coulombic efficiency (98% over 650 cycles), and Li + desolvation/transfer kinetics are obtained. Full cells pairing with the commercial LiFePO 4 (LFP) and LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cathodes show stable cyclability at both room-temperature and subzero conditions. Further electrolyte prototypes are showcased to demonstrate the universality of the design principle provided herein.