Perovskite‐type solid‐state electrolytes exhibit great potential for the development of all‐solid‐state lithium batteries due to their high Li‐ion conductivity (approaching 10−3 S cm−1), wide potential window, and excellent thermal/chemical stability. However, the large solid–solid interfacial resistance between perovskite electrolytes and electrode materials is still a great challenge that hinders the development of high‐performance all‐solid‐state lithium batteries. In this work, a perovskite‐type Li0.34La0.51TiO3 (LLTO) membrane with vertically aligned microchannels is constructed by a phase‐inversion method. The 3D vertically aligned microchannel framework membrane enables more effective Li‐ion transport between the cathode and solid‐state electrolyte than a planar LLTO membrane. A significant decrease in the perovskite/cathode interfacial resistance, from 853 to 133 Ω cm2, is observed. It is also demonstrated that full cells utilizing LLTO with vertically aligned microchannels as the electrolyte exhibit a high specific capacity and improved rate performance.

Ceramic oxide electrolytes are outstanding due to their excellent thermostability, wide electrochemical stable windows, superior Li‐ion conductivity, and high elastic modulus compared to other electrolytes. To achieve high energy density, all‐solid‐state batteries require thin solid‐state electrolytes that are dozens of micrometers thick due to the high density of ceramic electrolytes. Perovskite‐type Li0.34La0.56TiO3 (LLTO) freestanding ceramic electrolyte film with a thickness of 25 µm is prepared by tape‐casting. Compared to a thick electrolyte (>200 µm) obtained by cold‐pressing, the total Li ionic conductivity of this LLTO film improves from 9.6 × 10−6 to 2.0 × 10−5 S cm−1. In addition, the LLTO film with a thickness of 25 µm exhibits a flexural strength of 264 MPa. An all‐solid‐state Li‐metal battery assembled with a 41 µm thick LLTO exhibits an initial discharge capacity of 145 mAh g−1 and a high capacity retention ratio of 86.2% after 50 cycles. Reducing the thickness of oxide ceramic electrolytes is crucial to reduce the resistance of electrolytes and improve the energy density of Li‐metal batteries.

Separator modification has been proved to be an effective approach for overcoming lithium polysulfide (LiPS) shuttling in lithium-sulfur (Li-S) cells. However, the weight and stability of the modified layer also affect the cycling properties and the energy density of Li-S cells. Here, we initially construct an ultrathin and lightweight MnO layer (380 nm, 0.014 mg cm) on a commercial polyethylene (PE) separator (MnO@PE) through a chemical self-assembly method. This MnO layer is tightly anchored onto the PE substrate because of the presence of oxygen-containing groups that form a relatively strong chemical force between the MnO nanoparticles and the PE substrate. In addition, the mechanical strength of the separator is not affected by this modification procedure. Moreover, because of the catalytic effect and compactness of the MnO layer, the MnO@PE separator can greatly suppress LiPS shuttling. As a result, the application of this MnO@PE separator in Li-S batteries leads to high reversible capacity and superior cycling stability. This strategy provides a novel approach to separator surface modification.

Operating as the "rocking-chair" battery, sodium ion battery (SIB) with acceptable high capacity is a very promising energy storage technology. Layered vanadium oxide xerogel exhibits high sodium storage capacity. But it undergoes large lattice breathing during sodiation/desodiation, resulting in fast capacity fading. Herein, we develop a facile hydrothermal method to synthesize iron preintercalated vanadium oxide ultrathin nanobelts (Fe-VOx) with constricted interlayer spacing. Using the Fe-VOx as cathode for SIB, the lattice breathing during sodiation/desodiation is largely inhibited and the interlayer spacing is stabilized for reversible and rapid Na(+) insertion/extraction, displaying enhanced cycling and rate performance. This work presents a new strategy to reduce the lattice breathing of layered materials for enhanced sodium storage through interlayer spacing engineering.

Composite polymer electrolytes using polyethylene oxide (PEO) are highly appealing by virtue of the fine electrochemical stability, inexpensiveness, and easy fabrication. However, their practical application is currently hindered by the insufficient room-temperature ionic conductivity. Herein, nickel-based ultrathin metal−organic framework nanosheets (NMS) are first introduced as a novel 2D filler into the PEO matrix. The introduction of NMS with a high aspect ratio effectively improves the amorphous region proportion of PEO and thus enhances the ionic conductivity of the electrolyte by 1 order of magnitude. In addition, the Lewis acid−base interactions between the surface-coordinated unsaturated Ni atoms in NMS and the anions of lithium salt could promote the dissociation of lithium salt. Hence, the composite electrolyte with NMS achieves a high Li + transference value of 0.378. Along with the unique nanostructure of NMS, this NMS composite electrolyte also suppresses Li dendrite growth during cycling. As a result, the assembled all-solid-state Li/LiFePO 4 battery demonstrates a high reversible capacity of 130 mA h g −1 at 0.1 C and 30 °C for 50 cycles.