Because of the superiority of low cost and high theoretical capacity, sodium metal batteries are considered an attractive option for high energy storage. However, the uncontrollable and random deposition of Na tends to expedite the formation of Na dendrites and increases the risk of thermal runaway. The method of preplant sodiophilic sites can induce the lateral deposition of Na instead of sharp dendrite emergence. Here, we introduce the sodiophilic V2O3 particles to form a protective layer on Na surface (Na/V2O3). The high Na ion adsorption energy and low nucleation overpotential of Na/V2O3 facilitate the diffusion of Na ions and homogeneous Na deposition, which can work well in cubing dendrite development. Thus, the symmetrical cell (Na/V2O3||Na/V2O3) can stably operate for 670 h at 0.5 mA·cm−2/1 mAh·cm−2 with a smaller voltage hysteresis (less than 100 mV). Moreover, full cell constructed by coupling Na/V2O3 anode with Na3V2(PO4)3 cathode displays an outstanding rate performance, maintaining a high capacity of 70 mAh·g−1 at 30 C. On the basis of the design of sodiophilic protection layer, a dendrite-free, outstanding rate performance, and long lifespan sodium metal battery is realized.
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Lithium ion batteries (LIBs) that can be operated under extended temperature range hold significant application potentials. Here in this work, we successfully synthesized Co2V2O7 electrode with rich porosity from a facile hydrothermal and combustion process. When applied as anode for LIBs, the electrode displayed excellent stability and rate performance in a wide range of temperatures. Remarkably, a stable capacity of 206 mAh·g-1 was retained after cycling at a high current density of 10 A·g-1 for 6,000 cycles at room temperature (25 °C). And even when tested under extreme conditions, i.e., -20 and 60 °C, the battery still maintained its remarkable stability and rate capability. For example, at -20 °C, a capacity of 633 mAh·g-1 was retained after 50 cycles at 0.1 A·g-1; and even after cycling at 60 °C at 10 A·g-1 for 1,000 cycles, a reversible capacity of 885 mAh·g-1 can be achieved. We believe the development of such electrode material will facilitate progress of the next-generation LIBs with wide operating windows.