With the development of lithium ion batteries (LIBs), further increasing the energy densities of batteries is urgent. Graphene, with excellent chemical stability, high conductivity, and light weight, is an ideal material to improve the battery energy density by replacing traditional metal current collectors. Accordingly, we report a large-size (120 mm × 120 mm) graphene assembled film (GAF) with high crystallinity, electrical conductivity ((2.30 ± 0.06) × 10⁵ S m^–1) and ultralight weight (3.18 mg cm^–2). The electrode/GAF interface has better wetting and lower contact resistance. When all the metal (Al/Cu) current collectors are replaced by GAF, the energy density of the full cell electrode can increase by 32.9% (with an areal density of 4 mAh cm^–2). Moreover, the electrode with GAF current collectors shows improvements in cycling stability, rate capability, and capacity. Undoubtedly, these results suggest that GAF has broad prospects as a high-energy-density lithium ion current collector.

中文翻译：

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高度还原石墨烯组装膜作为锂离子电池的集电器

随着锂离子电池（LIBs）的发展，进一步提高电池的能量密度迫在眉睫。石墨烯具有优异的化学稳定性、高导电性和轻质等优点，是替代传统金属集流体提高电池能量密度的理想材料。因此，我们报告了一种大尺寸（120 mm × 120 mm）石墨烯组装膜（GAF），具有高结晶度、高导电性（(2.30 ± 0.06) × 10 ⁵ S m ^–1）和超轻重量（3.18 mg cm ^–2）。电极/GAF 界面具有更好的润湿性和更低的接触电阻。当所有金属（Al/Cu）集流体被GAF取代时，全电池电极的能量密度可提高32.9%（面密度为4 mAh cm^–2 )。此外，具有 GAF 集流体的电极在循环稳定性、倍率性能和容量方面均有所改善。毫无疑问，这些结果表明 GAF 作为一种高能量密度的锂离子集流体具有广阔的前景。