Point-line hybrid percolation conductive carbon networks in composite electrodes for high-power and durable aqueous Zn–V battery

Aqueous zinc-ion batteries (AZIBs) are promising for grid-scale energy storage, yet their cathodes often suffer from low electronic conductivity, which aggravates polarization and accelerates cycling-induced contact loss. Here, we clarify the role of conductive-network architecture in layered V 2 O 5 composite cathodes by fixing the external conductive carbon additive content at 10 wt% and systematically varying the mass ratio between 0D Ketjen black (KJ) and 1D vapor-grown carbon fibers (VGCF). The optimized formulation, denoted as KV55 with a KJ to VGCF ratio of 5 to 5, forms a hierarchical point-line hybrid electronic percolation network in composite electrodes, in which VGCF provides a continuous long-range conductive scaffold and KJ generates dense local contact nodes that bridge active particles and fibers. As a result, KV55 achieves the highest in-plane conductivity of 24.65 S cm −1 and the lowest interfacial charge-transfer resistance among the tested electrodes, leading to reduced polarization and improved rate capability. It delivers a high reversible capacity of 475.8 mAh g −1 at 0.2 A g −1 and sustaining 250.1 mAh g −1 at 20 A g −1 . Under long-term cycling at 10 A g −1 , KV55 maintains 341.6 mAh g −1 after 4000 cycles, corresponding to 87.8% capacity retention. These results provide a practical guideline for constructing carbon-efficient conductive networks that mitigate electronic-transport limitations and stabilize electrode contacts in low-conductivity layered cathodes.