A Silicon Monoxide Lithium-Ion Battery Anode with Ultrahigh Areal Capacity

Silicon monoxide(SiO) is an attractive anode material for next-generation lithium-ion batteries for its ultra-high theoretical capacity of 2680 m Ahg-1. The studies to date have been limited to electrodes with a relatively low mass loading(< 3.5 mg cm-2), which has seriously restricted the areal capacity and its potential in practical devices. Maximizing areal capacity with such high-capacity materials is critical for capitalizing their potential in practical technologies. Herein, we report a monolithic three-dimensional(3 D) large-sheet holey graphene framework/Si O(LHGF/Si O) composite for high-mass-loading electrode. By specifically using large-sheet holey graphene building blocks, we construct LHGF with super-elasticity and exceptional mechanical robustness, which is essential for accommodating the large volume change of Si O and ensuring the structure integrity even at ultrahigh mass loading. Additionally, the 3 D porous graphene network structure in LHGF ensures excellent electron and ion transport. By systematically tailoring microstructure design, we show the LHGF/Si O anode with a mass loading of 44 mg cm-2 delivers a high areal capacity of 35.4 m Ah cm-2 at a current of 8.8 m A cm-2 and retains a capacity of 10.6 m Ah cm-2 at 17.6 m A cm-2, greatly exceeding those of the state-of-the-art commercial or research devices. Furthermore, we show an LHGF/Si O anode with an ultra-high mass loading of 94 mg cm-2 delivers an unprecedented areal capacity up to 140.8 m Ah cm-2. The achievement of such high areal capacities marks a critical step toward realizing the full potential of high-capacity alloy-type electrode materials in practical lithium-ion batteries.