Silicon monoxide (SiO) is widely recognized as a promising anode material for next-generation lithium-ion batteries. Owing to its metastable amorphous structure, SiO exhibits a highly complex degree of crystallization at the microscopic level, which significantly influences its electrochemical behavior. As a consequence, accurately regulating the crystallization of SiO, and further establishing the relationship between crystallinity and electrochemical performance are very critical for SiO anodes. In this article, carbon-coated SiO materials with different crystallinity degrees were synthesized using lithium hydroxide monohydrate (LiOH·H₂O) as a structural modifier to reveal this rule. Additionally, moderate amount of LiOH·H₂O addition results in the forming of an oxygen-rich shell, which effectively inhibits the inward migration of oxygen atoms on the SiO surface and suppresses volume expansion. However, the crystallinity of SiO will gradually enhance and the crystalline phase appears with increasing the amount of LiOH·H₂O, which will generate a deteriorative Li⁺ diffusion kinetic. After balancing the above two contradictions, a mass fraction of 1% LiOH·H₂O for the additive yielded SiO@C-1, characterized by optimal crystallinity. SiO@C-1 demonstrates exceptional long-cycle stability with 74.8% capacity retention after 500 cycles at 1 A·g⁻¹. Furthermore, it achieves a capacity retention of 52.2% even at a high density of 5 A·g⁻¹. This study first reveals the relationship between SiO crystallinity and electrochemical performance, which efficiently guides the design of high-performance SiO anodes.

The commercialization of lithium-sulfur (Li-S) batteries faces several bottlenecks, and the major two of which are the shuttle effect of polysulfides and the wild growth of Li dendrites, responsible for fast capacity decay and severe safety issues. As an essential component of Li-S batteries, the structure and properties of the separators are closely related to the above problems, and the exploration of multifunctional separators is highly sought-after. Herein, an integrated separator composited of defective graphene and polyimide (DG-PI) was innovatively fabricated by electrospinning combined with the laser-induced carbonization strategy. The all-in-one compact architecture with well-interconnected channels shows superior mechanical and thermal stability and wettability. More importantly, the PI nanofibers containing N–/O– functional groups can induce the uniform deposition of lithium on the anode surface, while the DG framework with abundant pentagonal/heptagonal rings and vacancies can strongly trap polysulfides and accelerate polysulfide transformation on the cathode side. The strong chemical interaction between the insulative PI layer and the conductive DG layer modulates the surface charge distribution of each other, leading to more prominent contributions to restraining lithium dendrites and shuttle effect. Therefore, the Li-S batteries based on the integrated DG-PI separators afford an excellent performance in protecting lithium anode (stable cycles of 200 h at 5 mA·cm⁻²) and good cycling stability with a low capacity decay of 0.05% per cycle after 700 cycles at 1 C. This work offers a new design concept of multifunctional Li-S battery separators and broadens the application scope of laser micro-nano fabrication technology.