The sodium storage performance of a hard carbon (HC) anode in ether electrolytes exhibits a higher initial Coulombic efficiency (ICE) and better rate performance compared to conventional ester electrolytes. However, the mechanism behind faster Na storage kinetics for HC in ether electrolytes remains unclear. Herein, a unique solvated Na+ and Na+ co‐intercalation mechanism in ether electrolytes is reported using designed monodispersed HC nanospheres. In addition, a thin solid electrolyte interphase film with a high inorganic proportion formed in an ether electrolyte is visualized by cryo transmission electron microscopy and depth‐profiling X‐ray photoelectron spectroscopy, which facilitates Na+ transportation, and results in a high ICE. Furthermore, the fast solvated Na+ diffusion kinetics in ether electrolytes are also revealed via molecular dynamics simulation. Owing to the contribution of the ether electrolytes, an excellent rate performance (214 mAh g−1 at 10 A g−1 with an ultrahigh plateau capacity of 120 mAh g−1) and a high ICE (84.93% at 1 A g−1) are observed in a half cell; in a full cell, an attractive specific capacity of 110.3 mAh g−1 is achieved after 1000 cycles at 1 A g−1.

Extremely fast charging (XFC) is currently a crucial technology for lithium-ion batteries (LIBs) for addressing the concerns over the range and charging problems of electric vehicles. However, attaining both a high power density and a high energy density is a known challenge in electrochemical systems. Here, we report that Li3V2(PO4)3 can be an XFC cathode for high-voltage LIBs. Contrary to conventional belief, Li3V2(PO4)3 at a cutoff voltage (named CoV hereafter) of 4.8 V exhibits a rate performance and a cyclability that are better than those at a CoV of 4.3 V. The energy density based on an electrode can even exceed the theoretical value of LiFePO4, and the power density is comparable to that obtained from supercapacitors. Empirical characterizations are complemented with first-principles density functional theory calculations to determine the reaction mechanism and the diffusion pathways of the third Li+ in Li3V2(PO4)3. Moreover, the slow capacity decay mechanism of Li3V2(PO4)3 at a high CoV was elucidated by the differential capacity curve method.

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Solid‐state electrolytes (SSEs) with sufficient ionic conduction, wide voltage window, flexible‐rigid interface, and ease of processibility are determinative to the development of energy‐dense solid‐state lithium metal batteries. Due to the low density and interfacial compatibility, polyether SSE has been studied for decades but remains handicapped by the inherently low ionic conductivity and insufficient voltage window. In this contribution, an ion‐dipole‐reinforced poly‐3‐hydroxymethyl‐3‐methyloxetane is demonstrated as a novel SSE and major substitution to conventional poly(ethylene oxide). By further polypropylene skeleton compositing, the composite solid electrolyte (PHMP) synergistically achieves high voltage tolerance (4.6 V), high ion‐conduction (25 °C, 1.26 × 10−4 S cm−1), and flexible‐rigid mechanical properties. Cryo‐transmission electron microscope has revealed a columnar Li deposition and LiF‐rich solid electrolyte interface, suggesting excellent dendrite suppression. According to density functional theory, the densely branched ether–oxygen groups play an important role as ion solvation cages, favoring strong Li+‐coordination and fast diffusion kinetics. More importantly, it restrains the proton‐induced decomposition and essentially enhances high‐voltage stability. As a result, PHMP contributes to an improved rate capability, significantly reduced interface impedance, and long‐term cycle stability of Li symmetrical batteries for over 1600 h. PHMP‐modified LiNi0.8Co0.1Mn0.1O2|Li batteries exhibit a high discharge capacity of 211.5 mAh g−1 and desirable cycle stability.

Nitrogen doping carbon materials are considered to be promising candidates for Na+ storage anodes. However, hitherto, the effects and mechanism of specific single N configuration (among pyrrolic N, quaternary N, and pyridinic N), on the sodium storage behaviors of carbon materials, are still puzzling, owing to the difficulties in accurately synthesizing a certain type of single N configuration dominated carbon materials (NCDCMs). Here, various NCDCMs have been successfully controlled and synthesized by small molecule polymerization methods, and their synthesis process has been also verified by NMR, MOLDI-TOF, TG-MS, etc. When serving as sodium ion battery anodes, the NCDCMs dominated by a high concentration of pyrrolic N (>80.3%) exhibits a satisfactory reversible capacity (434.5 mA h g–1 at 50 mA g–1 and 146.7 mA h g–1 at 2000 mA g–1, respectively). It is revealed that pyrrolic N has more suitable adsorption energy and larger interlayer spacing, by density functional theory calculations and electron orbital theory, respectively, which synergistically makes the material obtain excellent electrochemical performance. This research exhibits a more efficient way to reveal the differences in the sodium ions storage behavior of different nitrogen configurations doped carbon, and provides new insight for the precise design and synthesis of a certain type of heteroatom doping to achieve satisfactory electrochemical performance.

Reducing charge−discharge overpotential of transition metal oxide catalysts can eventually enhance the cell efficiency and cycle life of Li−O 2 batteries. Here, we propose that crystal phase engineering of transition metal oxides could be an effective way to achieve the above purpose. We establish controllable crystal phase modulation of the binary Mn x Co 1−x O by adopting a cation regulation strategy. Systematic studies reveal an unprecedented relevancy between charge overpotential and crystal phase of Mn x Co 1−x O catalysts, whereas a dramatically reduced charge overpotential (0.48 V) via a rational optimization of Mn/Co molar ratio = 8/2 is achieved. Further computational studies indicate that the different morphologies of Li 2 O 2 should be related to different electronic conductivity and binding of Li 2 O 2 on crystal facets of Mn x Co 1−x O catalysts, finally leading to different charge overpotential. We anticipate that this specific crystal phase engineering would offer good technical support for developing highperformance transition metal oxide catalysts for advanced Li−O 2 batteries.

Lithium metal batteries (LMBs) are among the most promising candidates for high energy-density batteries. However, dendrite growth constitutes the biggest stumbling block to its development. Herein, Li4SiO4-dominating organic–inorganic hybrid layers are rationally designed by SiO2 surface modification and the stepwise prelithiation process. SiO2 nanoparticles construct a zigzagged porous structure, where a solid electrolyte interface (SEI) has grown and penetrated to form a conformal and compact hybrid surface. Such a first-of-this-kind structure enables enhanced Li dendrite prohibition and surface stability. The interfacial chemistry reveals a two-step prelithiation process that transfers SiO2 into well-defined Li4SiO4, the components of which exhibits the lowest diffusion barrier (0.12 eV atom–1) among other highlighted SEI species, such as LiF (0.175 eV atom–1) for the current artificial layer. Therefore, the decorated Li allows for an improved high-rate full-cell performance (LiFePO4/modified Li) with a much higher capacity of 65.7 mAh g–1 at 5C (1C = 170 mAh g–1) than its counterpart with bare Li (∼3 mAh g–1). Such a protocol provides insights into the surface architecture and SEI component optimization through prelithiation in the target of stable, dendrite-proof, homogenized Li+ solid-state migration and high electrochemical performance for LMBs.

In NaMnO2, Na ion diffusion is assisted by the Jahn–Teller type small polaron under both charged and discharged states.