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Poly(ethylene oxide) (PEO)-based polymer electrolytes have been widely studied as a result of their flexibility, excellent interface contact, and high compatibility with a lithium metal anode. Owing to the poor oxidation resistance of ethers, however, the PEO-based electrolytes are only compatible with low-voltage cathodes, which limits their energy density. Here, a high-voltage stable solid-state interface layer based on polyfluoroalkyl acrylate was constructed via

Nickel-rich Li(NixCoyMn1-x-yO2) (x ≥ 0.6) is considered to be a predominant cathode for next-generation lithium-ion batteries (LIBs) due to its towering specific energy density. Unfortunately, serious structural degradation causes rapid capacity degradation with the increase in nickel content. Herein, a Co and Ti co-modified LiNi0.8Co0.1Mn0.1O2 (NCM-811) cathode ameliorates the reversible capacity together with the rate capability by obviously alleviating the lattice structure degradation and microscopic intergranular cracks. Further studies show that the titanium doping effectively reduces the cation mixing and also stabilizes the crystal structure, while the spinel phase formed at the surface by a cobalt oxide coating is much stable than the layered phase at high voltage, which can alleviate the generation of micro-cracks. After 0.5% Co oxide coating and 1% Ti doping (T1Co0.5-NCM), a superior rate capability (121.75 mA h g-1 at 20 C between 2.7 and 4.5 V) and predominant capacity retention (74.2%) are observed compared with the pristine NCM-811 (59.5%) after 400 cycles between 2.7 and 4.7 V. This work supplies an eminent design of high-voltage and high-rate layered cathode materials and has a huge application prospect in the next generation of high-energy LIBs.

Replacing organic porous separators with an inorganic solid-state electrolyte (SSE) is a promising strategy to suppress lithium dendrite and inhibit polysulfide dissolution in lithium-sulfur (Li-S) batteries. However, the realization of such a concept is still limited by the large interfacial resistance between SSE and lithium anode. Herein, a new electrolyte additive, copper fluoride (CuF2), is used in liquid electrolytes to construct a stable interphase between Li1.5Al0.5Ge1.5(PO4)3 (LAGP) SSE and Li metal for a quasi-solid-state Li-S battery. A Li||Li symmetric cell with ultralong life over 1500 h (at 0.1 mA cm-2) proves the excellent stability of the as-formed interphase. As a result, the assembled Li-S full cell presents high coulombic efficiency and stable cycling (750 mA h g-1 after 50 cycles) at room temperature with lean liquid electrolytes. This strategy provides an effective method for improving the electrochemical performance of Li-S batteries.

We are presenting a sol-gel method for building novel nanostructures made of nanosized F-doped Na

A novel solid sodium-ion conductor, Na