Surfacing Amorphous Ni-B Nanoflakes On Nico2o4 Nanospheres As Multifunctional Bridges For Promoting Lithium Storage Behaviors

Transition metal oxides (TMOs) have gained enormous research interests as negative materials of next generation lithium-ion batteries due to their higher energy density, lower cost, and better eco-friendliness. However, they are prone to low electronic conductivities and dramatic volume change during charge/discharge and there is also a great challenge in realizing TMO electrodes with satisfactory LIB performances. In this study, for the first time, amorphous nickel-boride (Ni-B) was introduced into porous NiCo2O4 nanospheres by an in situ solution growth route to overcome the existing issues. The coated Ni-B component could not only function as anchors for NiCo2O4 nanospheres to suppress the severe volume expansion but could also act as effective electron-conducting bridges to promote fast electron/ charge transfer. Furthermore, the existence of abundant mesopores centered at similar to 6.5 nm in this composite could effectively suppress the severe volume variations in the lithiation/delithiation process. As expected, the NiCo2O4@Ni-B composites delivered a high reversible capacity of 1221 mA h g(-1) at 0.2 A g(-1) and 865 mA h g(-1) at 0.5 A g(-1) over 500 cycles; more impressively, at the high rate of 5 A g(-1), a capacity of 648 mA h g(-1) could be also obtained, showing its good rate capability. As a result, these results demonstrated an effective and facile way to design conversion-type negative electrode materials with superior lithium storage properties.