Improving one property without sacrificing others is challenging for lithium-ion batteries due to the trade-off nature among key parameters. Here we report a chemical vapor deposition process to grow a graphene–silica assembly, called a graphene ball. Its hierarchical three-dimensional structure with the silicon oxide nanoparticle center allows even 1 wt% graphene ball to be uniformly coated onto a nickel-rich layered cathode via scalable Nobilta milling. The graphene-ball coating improves cycle life and fast charging capability by suppressing detrimental side reactions and providing efficient conductive pathways. The graphene ball itself also serves as an anode material with a high specific capacity of 716.2 mAh g−1. A full-cell incorporating graphene balls increases the volumetric energy density by 27.6% compared to a control cell without graphene balls, showing the possibility of achieving 800 Wh L−1 in a commercial cell setting, along with a high cyclability of 78.6% capacity retention after 500 cycles at 5C and 60 °C.
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机译：由于关键参数之间的折衷性质，在不牺牲其他性能的情况下改善一种性能对于锂离子电池而言是一项挑战。在这里，我们报告了一种化学气相沉积过程，用于生长称为石墨烯球的石墨烯-二氧化硅组件。它具有氧化硅纳米粒子中心的分层三维结构，允许通过可缩放的Nobilta研磨，甚至将1 wt％的石墨烯球均匀地涂覆到富镍层状阴极上。石墨烯球涂层通过抑制有害的副反应并提供有效的导电路径，提高了循环寿命和快速充电能力。石墨烯球本身也用作阳极材料，具有716.2 mAh g -1 的高比容量。与不含石墨烯球的对照组电池相比，掺入石墨烯球的全电池组将体积能量密度提高了27.6％，这表明在商用电池组环境中实现800 Wh L -1 的可能性。在5C和60°C下进行500次循环后，具有78.6％的容量保持率的高循环能力。
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