All-solid-state lithium batteries (ASSLBs) employ high-capacity lithium (Li) metal as the anode and exhibit a higher energy density than that of conventional Li-ion batteries. However, the problems arose from the Li dendrites induce severely parasitic reaction between Li and electrolytes, leading to low coulombic efficiency (CE) and poor cyclic stability. Herein, a poly(vinylidene-co-hexafluoropropylene)/lithium nitrate (PVDF-HFP/LiNO₃, marked as PFH/LN) artificial layer is employed to modified Li and achieve high CE ASSLBs with polyethylene oxide-Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (PEO-LLZTO) electrolyte. LN serves as a functionalized additive to facilitate the formation of a robust solid electrolyte interface (SEI), efficiently suppressing the formation of Li dendrites. Additionally, LN as a "binder" effectively links PFH with Li, providing good contact. PFH possesses high mechanical strength and moderate flexibility, which can not only physically inhibit the growth of Li dendrites, but also maintain the structural integrity of artificial layer over long-term cycles. Finally, Li/Li cells with such artificial layer demonstrate ultralong cycle life of 1800 and 1000 h under 0.2 and 0.4 mA cm⁻¹, respectively. Furtherly, high CE can be achieved when applied in both LiFePO₄ full cells and Li-Cu half cells. This work offers a facile and efficient strategy to greatly promote CE in PEO-based ASSLBs.

Due to easy re-stacking, low yield of few-layered MXenes (f-MXenes), the applications of MXenes are mainly restricted in multi-layered MXenes (m-MXenes) state. Although f-MXenes can be prepared from m-MXenes, after exfoliation process, a mass of sediments which are still essentially compact MXenes are usually directly discarded, leading to low utilization of raw m-MXenes. Herein, a classified preparation strategy is adopted to exploit the raw m-MXenes and traditional MXenes sediments, taking multi-layered Ti₃C₂T_x MXene as an example. Via rational delamination and subsequent treatment to Ti₃C₂T_x sediments, we succeed in achieving classified and large-scale preparation of various Ti₃C₂T_x MXene derivatives, including few-layered Ti₃C₂T_x (f-Ti₃C₂T_x) powders, f-Ti₃C₂T_x films, and Ti₃C₂T_x MXene-derived nanowires with heterostructure of potassium titanate and Ti₃C₂T_x. We demonstrate the necessity of “step-by-step delamination” towards traditional Ti₃C₂T_x sediments to improve the yield of f-Ti₃C₂T_x from 15% to 72%; the feasibility of “solution-phase flocculation (SPF)” to fundamentally solve the re-stacking phenomenon, and oxidation degradation issues of f-Ti₃C₂T_x during storage; as well as the convenience of SPF to deal with time-consuming issues of fabricating Ti₃C₂T_x films. What’s more, alkali-heat treatment of final Ti₃C₂T_x sediments turns waste into treasure of Ti₃C₂T_x-derived nanowires, leading to 100% utilization of raw Ti₃C₂T_x. The content of one-dimensional (1D) nanowires in the hybrids can be adjusted by controlling alkalization time. The 3D architecture heterostructure composed of 1D nanowires and 2D nanosheets exhibits gorgeous application potential. This work can expand preparation and application of various MXenes derivatives, promoting process of various MXenes.

Pillaring technologies have been considered as an effective way to improve lithium storage performance of Ti₃C₂T_x MXene. Nevertheless, the pillared hybrids suffer from sluggish Li⁺ diffusion kinetics and electronic transportation due to the compact multi-layered MXene structure, thus exhibiting inferior rate performance. Herein, the few-layered Ti₃C₂ MXene (f-Ti₃C₂ MXene) which is free from restacking can be prepared quickly based on the NH₄⁺ ions method. Besides, Fe nanocomplex pillared few-layered Ti₃C₂T_x (FPTC) heterostructures are fabricated via the intercalation of Fe ions into the interlayer of f-Ti₃C₂ MXene. The f-Ti₃C₂ MXene which is immune to restacking can provide a highly conductive substrate for the rapid transport of Li⁺ ions and electrons and possess adequate electrolyte accessible area. Moreover, f-Ti₃C₂ MXene can efficiently relieve the aggregation, prevent the pulverization and buffer the large volume change of Fe nanocomplex during lithiation/delithiation process, leading to enhanced charge transfer kinetics and excellent structural stability of FPTC composites. Consequently, the FPTC hybrids exhibit a high capacity of 535 mAh·g⁻¹ after 150 cycles at 0.5 A·g⁻¹ and an enhanced rate performance with 310 mAh·g⁻¹ after 850 cycles at 5 A·g⁻¹. This strategy is facile, universal and can be extended to fabricate various few-layered MXene-derived hybrids with superior rate capability.