Nickel–tin foam with nanostructured walls for rechargeable lithium battery

Nickel–tin foams with a graded micro-porous framework and nano-porous walls are created by an electrochemical deposition method for use as the anode in rechargeable lithium batteries. The resulting electrodes react readily with lithium electrochemically and deliver a reversible capacity of more than 470 mAh g−1 for up to 50 cycles. In addition, they show outstanding rate performance: their reversible capacity at a discharging rate of 20 C is about 70% of the capacity at a rate of 1 C, due mainly to their unique structure which allows facile lithium-ion transport and fast surface reactions. The reversible capacity and rate capability show strong dependence on the thickness of the deposit and this is associated with the accessibility of lithium ions inside the porous structure.

Research highlights
► Nickel–tin foams with a graded micro-porous framework and nano-porous walls were created for the first time by an electrochemical deposition method.
► The resulting material delivered a reversible capacity of more than 470 mAh g−1 for up to 50 cycles as the anode in rechargeable lithium battery.
► Its capacity retention at a discharging rate of 20 C was about 70% of the capacity at a rate of 1 C. This is outstanding rate performance exceeding that of the tin-based alloys reported previously.
► The structure presented herein is ideally suited for high-power applications where the rapid transport of lithium ions to the electrode/electrolyte interface and subsequent fast interfacial reaction are required.