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Ti2 Nb 1 0 O 2 9 (TNO) is considered as a potential anode material due to its high capacity/power density and reliable safety. However, its poor electronic conductivity restricts its rate performance, which is important for its application in electric vehicles (EVs). In this study, we fabricated a hybrid of Ti2 Nb 1 0 O 2 9 − x /holey-reduced graphene oxide (TNOx/HRGO) by a two-step method. In the structure of TNOx/HRGO, TNOx microspheres with oxygen vacancies are wrapped by gossamer-like HRGO. The oxygen vacancies of TNOx and the high conductivity of HRGO can effectively enhance the electronic conductivity of the TNOx/HRGO hybrid, and the HRGO holes are beneficial for the transmission of lithium-ion ( Li + ). The synergy effect of above features improves the rate performance of the TNOx/HRGO hybrid. In addition, the existence of HRGO can buffer volume expansion during the insertion processes of Li + , which can improve cyclic stability of the TNOx/HRGO hybrid. Consequently, the TNOx/HRGO electrode has excellent lithium-ion storage capacity, with high-rate performance (242 mAh/g at 10∘C, 225 mAh/g at 20∘C and 173 mAh/g at 40∘C) and excellent cyclic stability (98.0% capacity retention after 300 cycles at 10∘C). This work reveals that TNOx/HRGO can be a potential anode material for high-rate-performance lithium-ion storage. TNOx/HRGO hybrid was fabricated through solvothermal method, annealing, and freeze-drying, and its performance as anode of LIB was investigated. Due to its porous microstructure, the existence of oxygen vacancies and holey-reduced graphene oxide coating, the electronic conductivity and ionic conductivity of TNOx/HRGO were greatly improved, thus obtaining excellent high-rate performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual-layer nanoshell structure was constructed on the single-crystal particles via chemical methods. • Gd doping in the rock-salt phase epitaxial layer lowers O 2p electron energy, stabilizing surface lattice oxygen. • The modified sample shows 93.4% capacity retention at 1 C after 500 cycles, and 94.2% at 0.2 C after 200 cycles. Lithium-rich layered oxides (LLOs) have garnered significant attention due to their outstanding capacity. However, the severe capacity fading resulting from lattice deterioration initiated at the surface constrains the further advancement of LLOs. Here, we present a method to stabilize the surface lattice to enhance the capacity stability of LLOs. Specifically, we have engineered a nanometer-thin Gd-doped NiO rock-salt epitaxial layer on the surface of single-crystal LLOs, along with an atomic-level thickness LiGdO 2 coating layer. The dual-nanolayer protection strategy has successfully stabilized the surface structure of LLOs and suppressed electrode–electrolyte interface side reactions. As a result, the modified sample achieves a capacity retention rate of 93.4% after 500 cycles at 1C and 94.2% after 200 cycles at 0.2C. Our study underscores the importance of surface structure in achieving high cyclic stability in LLOs and provides an important approach for designing stable lithium-ion battery cathode materials. [ABSTRACT FROM AUTHOR]

Fast-charging lithium-ion batteries (LIBs) have recently received significant attention. In current commercial LIBs, lithium precipitation frequently occurs under long-term cycling and fast-charging conditions, adversely affecting their cycle capacity retention and safety. The primary cause of lithium precipitation is electrolyte loss during long-term cycling. In this study, a thermoplastic polyurethane/polyurethane acrylate semi-interpenetrating polymer network ceramic separator with high electrolyte retention (200%) and interfacial adhesion (6.6 N) is prepared and without a decrease in the energy density. The LiNi 0.8 Mn 0.1 Co 0.1 O 2 /graphite batteries fabricated with this separator show excellent electrochemistry properties (300 cycles, 1.5 C, discharge capacity of 3677 mAh, capacity retention of 93%). Furthermore, this study presents a novel strategy to mitigate the issue of lithium precipitation in fast-charging LIBs. Therefore, this functional separator is a promising alternative for the conventional commercial polyvinylidene difluoride separators and provides a new avenue for developing the next generation of fast-charging devices. [Display omitted] • The root cause of lithium precipitation in fast-charging conditions was explored. • A ceramic separator with semi-interpenetrating polymer network was prepared. • The separator displayed high electrolyte retention rate and interfacial adhesion. • The cell with the separator exhibited outstanding electrochemical performance. [ABSTRACT FROM AUTHOR]