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The demand for large-scale and safe energy storage is increasing rapidly due to the strong push for smartphones and electric vehicles. As a result, Li+/Mg2+ hybrid-ion batteries (LMIBs) combining a dendrite-free deposition of Mg anode and Li+ intercalation cathode have attracted considerable attention. Here, a LMIB with hydrothermal-prepared MoS2 nano flowers as cathode material was prepared. The battery showed remarkable electrochemical properties with a large discharge capacity (243 mAh g−1 at the 0.1 C rate), excellent rate capability (108 mAh g−1 at the 5 C rate), and long cycle life (87.2 % capacity retention after 2300 cycles). Electrochemical analysis showed that the reactions occurring in the battery cell involved Mg stripping/plating at the anode side and Li+ intercalation at the cathode side with a small contribution from Mg2+ adsorption. The excellent electrochemical performance and extremely safe cell system show promise for its use in practical applications. [ABSTRACT FROM AUTHOR]

Li-rich layered oxide Li1.18Ni0.15Co0.15Mn0.52O2 (LNCM) is, for the first time, examined as the positive electrode for hybrid sodium-ion battery and its Na+ storage properties are comprehensively studied in terms of galvanostatic charge-discharge curves, cyclic voltammetry and rate capability. LNCM in the proposed sodium-ion battery demonstrates good rate capability whose discharge capacity reaches about 90 mA h g−1 at 10 C rate and excellent cycle stability with specific capacity of about 105 mA h g−1 for 200 cycles at 5 C rate. Moreover, ex situ ICP-OES suggests interesting mixed-ions migration processes: In the initial two cycles, only Li+ can intercalate into the LNCM cathode, whereas both Li+ and Na+ work together as the electrochemical cycles increase. Also the structural evolution of LNCM is examined in terms of ex situ XRD pattern at the end of various charge-discharge scans. The strong insight obtained from this study could be beneficial to the design of new layered cathode materials for future rechargeable sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Carbon black (CB) and vapor-grown carbon fibers (VGCFs) are used as conductive additives for the Li 1.18 Co 0.15 Ni 0.15 Mn 0.52 O 2 electrodes for Li-ion batteries. The fibrous VGCFs can bridge the isolated Li 1.18 Ni 0.15 Co 0.15 Mn 0.52 O 2 regions, thus construct an effective conductive network for electron transport. In addition, incorporation of CB and VGCFs can improve the electrochemical kinetics of the cathode material by retarding the harmful side reactions, promoting the charge transfer reactions and increasing the apparent lithium diffusion coefficient. In all electrodes under investigation, the one prepared with 3 wt.% of VGCFs and 12 wt.% of CB shows the largest discharge capacity of 252 mAh g −1 at the 0.2C rate with excellent capacity retention and rate capability. [ABSTRACT FROM AUTHOR]

Titanium dioxide bronze (TiO 2 -B) nanowires were prepared by the hydrothermal method and used as the positive electrode for Mg rechargeable batteries and Li + /Mg 2+ hybrid-ion batteries. First-principles calculations showed that the diffusion barrier for Mg 2+ (0.6 eV) in the TiO 2 -B lattice was more than twice of that for Li + (0.3 eV). Electrochemical impedance spectroscopy showed that the charge transfer resistance of TiO 2 -B in the Mg 2+ ion electrolyte was much larger than that in the Li + /Mg 2+ hybrid electrolyte. For these reasons, the Mg rechargeable battery showed a small discharge capacity of 35 mAh g −1 resulting from an electrochemical double-layer capacitive process. In comparison, the TiO 2 -B nanowires exhibited a large capacity (242 mAh g −1 at the 20 mA g −1 current density), high rate capability (114 mAh g −1 at 1 A g −1 ), and excellent cycle stability in the Li + /Mg 2+ hybrid-ion battery. The dominant reaction occurred in the TiO 2 -B electrode was intercalation of Li + ions, of which about 74% of the total capacity was attributed to Li + pseudo-capacitance. [ABSTRACT FROM AUTHOR]