SnO2 suffers from fast capacity fading in lithium-ion batteries due to large volume expansion as well as unstable solid electrolyte interphase. Herein, the design and synthesis of phosphorus bridging SnO2 and graphene through covalent bonding are demonstrated to achieve a robust structure. In this unique structure, the phosphorus is able to covalently "bridge" graphene and tin oxide nanocrystal through PC and SnOP bonding, respectively, and act as a buffer layer to keep the structure stable during charging-discharging. As a result, when applied as a lithium battery anode, SnO2 @P@GO shows very stable performance and retains 95% of 2nd capacity onward after 700 cycles. Such unique structural design opens up new avenues for the rational design of other high-capacity materials for lithium battery, and as a proof-of-concept, creates new opportunities in the synthesis of advanced functional materials for high-performance energy storage devices.
Keywords: SnO2; covalent bonding; graphene; lithium-ion battery; ultrastable anode.
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