Yi Cui

Electrolytes using fluorinated solvents have proven effective in improving the cycling life of Li-metal batteries, by forming a robust solid–electrolyte interphase through decomposition of anion and fluorinated solvent molecules. Herein, we modulated the fluorination degree of ether-based electrolyte solvents to investigate their performance in Li-metal batteries. We tuned the fluorination degree by installing a monofluoro substituent on one ethoxy group of 1,2-diethoxyethane (DEE) and varying the fluorination degree on the other one, providing three fluorinated DEE solvent molecules (i.e., F1F0, F1F1 and F1F2) with a relatively low fluorination degree. All three electrolytes showed improved solvation strength and ionic conductivities compared with previous highly fluorinated DEE electrolytes while retaining good oxidative stability. A full cell test using the Li-metal anode and nickel-rich cathode revealed that a higher …

Achieving extremely fast charging yet maintaining high energy density remains a challenge in the battery field. Traditional current collectors, being impermeable to electrolytes, hinder the movement of Li+ ions and restrict the high-rate capability of thick electrodes. Here we conceptualize a porous current collector for energy-dense and extremely fast-charging batteries. This porous design allows Li+ ions to pass through both the current collector and the separator simultaneously, thereby reducing the effective Li+ transport distance by half and quadrupling the diffusion-limited C-rate capability without compromising the energy density. Multilayer pouch cells equipped with this current collector demonstrate high specific energy (276 Wh kg−1) and remarkable fast-charging capabilities at rates of 4 C (78.3% state of charge), 6 C (70.5% state of charge) and 10 C (54.3% state of charge). This porous current collector …

Safety issues have been a long-standing obstacle impeding large-scale adoption of next-generation high-energy-density batteries. Materials solutions to battery safety management are limited by slow response and small operating voltage windows. Here we report a fast and reversible thermoresponsive polymer switching material that can be incorporated inside batteries to prevent thermal runaway. This material consists of electrochemically stable graphene-coated spiky nickel nanoparticles mixed in a polymer matrix with a high thermal expansion coefficient. The as-fabricated polymer composite films show high electrical conductivity of up to 50 S cm− 1 at room temperature. Importantly, the conductivity decreases within one second by seven to eight orders of magnitude on reaching the transition temperature and spontaneously recovers at room temperature. Batteries with this self-regulating material built in the …

We performed Na NMR and magnetization measurements on an =1, quasi-2D honeycomb lattice antiferromagnet NaNiBiO. A large positive Curie-Weiss constant of 22.9 K is observed. The NMR spectra at low fields are consistent with a "zigzag" magnetic order, indicating a large easy-axis anisotropy. With field applied along the axis, the NMR spectra confirm the existence of a 1/3-magnetization plateau phase between 5.1 T and 7.1 T. The transition from the zigzag order to the 1/3-magnetization plateau phase is also found to be a first-order type. A monotonic decrease of the spin gap is revealed in the 1/3-magnetization plateau phase, which reaches zero at a quantum critical field 8.35 T before entering the fully polarized phase. These data suggest the existence of exchange frustration in the system along with strong ferromagnetic interactions, hosting the possibility for Kitaev physics. Besides, well …

The intriguing two-dimensional (2D) molybdenum disulfide (MoS2) has unique potential in next-generation nanoelectronics and optoelectronics, engendering intense interest in its synthesis, especially using chemical vapor deposition (CVD). However, achieving high-quality 2D MoS2 remains a challenge, primarily limited by substrate quality in most instances. Herein, we develop an elegant way to create atomic-level well-defined Au(111) single-crystal films by ultra-high-vacuum (UHV)-interconnected techniques, including sputtering, annealing, and imaging, avoiding the environmental-impurity damage during crystallization and surface reconstruction compared to normal atmosphere-based operation. Benefiting from substrate engineering, this work succeeded in the epitaxial growth of uniform MoS2 monolayers using the CVD approach and further investigated the growth dynamics affected by key factors. It was …

An anode includes:(1) a current collector; and (2) an interfacial layer disposed over the current collector. The interfacial layer includes an ion-conductive organic network including anionic coordination units, organic linkers bonded through the anionic coordination units, and counterions dispersed in the ion-conductive organic network.

In the online version of the article initially published, a PDF from a different article was included. This has now been corrected, and the PDF of this article is available to view online.

In the pursuit of high-performance solid-state batteries (SSBs), which can have excellent safety and energy density, it is critical to understand the cyclability of emerging classes of solid-state electrolytes (SSEs). Lithium thioborates (LBS) are an understudied class of materials with promising applications in SSBs with lithium metal anodes. We investigate the electrochemistry, structure, and cyclability of the LBS SSE with stoichiometric Li10B10S20 with lithium iodide (LiI) as an additive. LBS-LiI exhibits an outstanding ionic conductivity of 1.0 mS cm–1 due to increased LBS crystallinity and favorable modification of the LBS grain boundaries with LiI. LiI improves the cycling stability against lithium metal anodes, limits dendrite growth with a high critical current density of 2.0 mA cm–2, and cycles well in cells with LiNi0.6Mn0.2Co0.2O2 (NMC) 622 cathodes and indium anodes. Our work highlights LiI as a grain boundary …