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[Display omitted] • Highly active nanocrystalline NCM 811 precursor particles were prepared via a microfluidic technology. • The single-crystal NCM 811 material has high a degree of cationic order, excellent elemental distribution, small size (<3 μm). • The as-prepared single-crystal NCM811 material can well balance the cycle and rate performance. Single-crystal LiNi x Mn y Co 1-x-y O 2 (SC-NMC) cathode with electro-chemo-mechanically compliant microstructure is regarded as a promising candidate for high-energy–density lithium ion battery. However, the research of Ni-rich SC-NCM still lags behind its corresponding polycrystalline cathode materials, mainly due to the difficulties in synthesis. Herein, the single-crystal LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode (SC-NCM811) was successfully synthesized by microfluidic technology combined with the solid-state lithiation process. The nano-sized Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursor prepared via microfluidic technology enhances its accessibility to lithium salts, thus exhibiting high chemical activity for lithiation reaction. As a result, the optimized SC-NCM811 cathode shows relatively small-scale grain size (<3 μm), low cation mixing and well layered structure, which is beneficial to electrochemical kinetics and redox reversibility. The electrochemical characterization results further reveal that the optimized SC-NCM811 cathode can well balance the cycle performance and rate capability, showing good electrochemical performance. Overall, microfluidic technology is expected to provide a new strategy for preparing single-crystal Ni-rich cathode materials, which may extend to the commercial application of other cathode materials. [ABSTRACT FROM AUTHOR]

Poor stability of lithium metal anodes in liquid electrolytes hinders its practical application in rechargeable batteries with very high energy density. Herein, we present an approach to tackle the intrinsic problems of Li metal anodes from the standpoint of separators. By a facile and versatile method based on mussel-inspired surface chemistry, a hybrid polydopamine/octaammonium POSS (PDA/POSS) coating was spontaneously formed on the surface of PE separators through the self-polymerization and strong adhesion feature of dopamine. This ultrathin PDA/POSS coating endows PE separators with different surface characteristics while keeping its microporous structure almost unchanged. The altered surface characteristics influence the separator/electrolyte interaction, and lead to remarkable enhanced ionic conductivity (from 0.36 mS cm −1 to 0.45 mS cm −1 ) and Li + ion transference number (from 0.37 to 0.47) of PE separators as well as the improved stability of lithium/electrolyte interface, which effectively decreases the electrode polarization and suppresses the lithium dendrites formation, contributing to superior C-rates capability and cycling performance of cells. [ABSTRACT FROM AUTHOR]

The electrochemical performance of lithium-ion batteries are affected by the anode materials. SnO is an important anode material due to its high theoretical specific capacity of about 783 mAh/g for next-generation lithium-ion batteries with a higher energy density. In this work, we combined the electrochemical advantages of graphene and TiO, and the Ti-doped composites of SnO/reduced graphene oxide as the anode materials were fabricated by a hydrothermal method. To analyze the structure and electrochemical properties, a series of characterizations including X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements were performed. The results confirmed that Ti atoms effectively replaced Sn atoms, improving the long-term cycling stability, which exhibited a superior rate capability and maintained a high discharge capacity around 500 mAh/g after 200 cycles. [ABSTRACT FROM AUTHOR]

Low Li + ion transference number is one fatal defect of the liquid LiPF 6 electrolyte for Li-metal anode based batteries. This work aims to improve Li + ion transference number and ionic conductivity polyethylene (PE) separators. By a simple dip-coating method, the water-borne nanosized molecular sieve with 3D porous structure (ZSM-5) can be coated on PE separators. Especially, the Li + ion transference number is greatly enhanced from 0.28 to 0.44, which should be attributed to the specific pore structure and channel environment of ZSM-5 as well as the interaction between ZSM-5 and electrolyte. Compared with the pristine PE separator, the ionic conductivity of modified separators is remarkably improved from 0.30 to 0.54 mS cm −1 . As results, the C-rate capability and cycling stability are both improved. The Li-metal battery using the ZSM-5-modified PE separator keeps 94.2% capacity after 100 cycles. In contrast, the discharge capacity retention of the battery using pristine PE is only 74.7%. [ABSTRACT FROM AUTHOR]