<p>Layered O3-type sodium transition metal oxides are competitive cathode candidates for sodium-ion batteries (SIBs), but their commercialization is hindered by sluggish Na⁺ transport, irreversible phase transitions, interlayer slippage, and poor cycling durability. Herein, we propose a Zn²⁺ doping strategy via a low-cost scalable high-temperature solid-state route. Systematic characterizations confirm optimal Zn²⁺ doping (x = 0.03) improves structural stability and electrochemical performance. XRD and Rietveld refinement show Zn²⁺ incorporation enlarges Na layer spacing from 3.1741 Å to 3.1835 Å and TM layer spacing from 2.1475 Å to 2.1559 Å, while moderate Zn-O bond energy balances lattice stability and Na⁺ mobility. XPS verifies stable Zn²⁺ existence, inhibiting Mn³⁺ disproportionation. The optimized NFM-Zn_0.03 delivers 162 mAh g^–1 at 0.1&#xa0;C, 81.4% retention after 100 cycles at 1&#xa0;C, 74 mAh g^–1 at 10&#xa0;C, and a Na⁺ diffusion coefficient (7.59 × 10^–10cm² s^–1) 1.9-fold higher than the undoped sample, consistently corroborated by GITT, CV, and EIS measurements. This work provides a low-cost, structure-oriented Zn doping strategy for high-performance SIB cathodes.</p>