Graphite’s capacity of intercalating lithium in rechargeable batteries is limited (theoretically, 372 mAh g−1) due to low diffusion within commensurately-stacked graphene layers. Graphene foam with highly enriched incommensurately-stacked layers was grown and applied as an active electrode in rechargeable batteries. A 93% incommensurate graphene foam demonstrated a reversible specific capacity of 1,540 mAh g−1 with a 75% coulombic efficiency, and an 86% incommensurate sample achieves above 99% coulombic efficiency exhibiting 930 mAh g−1 specific capacity. The structural and binding analysis of graphene show that lithium atoms highly intercalate within weakly interacting incommensurately-stacked graphene network, followed by a further flexible rearrangement of layers for a long-term stable cycling. We consider lithium intercalation model for multilayer graphene where capacity varies with N number of layers resulting LiN+1C2N stoichiometry. The effective capacity of commonly used carbon-based rechargeable batteries can be significantly improved using incommensurate graphene as an anode material.
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机译：石墨在可充电电池中嵌入锂的能力受到限制（理论上为372 mAh g -1 ），这是由于在相应堆叠的石墨烯层中扩散程度较低。生长具有高度富集的不适当堆积层的石墨烯泡沫，并将其用作可充电电池中的活性电极。 93％不相称的石墨烯泡沫材料的可逆比容量为1,540 mAh g -1 ，库仑效率为75％； 86％不相称的样品达到了99％以上的库仑效率，显示930 mAh g -1 特定容量。石墨烯的结构和结合分析表明，锂原子高度嵌入弱相互作用的不相称地堆叠的石墨烯网络中，随后层进一步灵活重排以实现长期稳定的循环。我们考虑了多层石墨烯的锂嵌入模型，其中容量随N层数的变化而变化，从而导致LiN + 1C2N化学计量。使用不相称的石墨烯作为负极材料，可以显着提高常用碳基可充电电池的有效容量。
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