• • FeNi3/CNS electrocatalyst delivers a rate capability of 852 mAh g−1 at 3.0 C, demonstrating superior high-rate performance for Li–S batteries.
• • Long-term cycling stability is achieved with 639 mAh g−1 retained after 500 cycles at 1.0 C, indicating excellent capacity retention for practical applications.
• • The catalyst enables stable operation across a wide temperature range from −15°C to 60°C, addressing performance degradation under extreme thermal conditions.
• • A maximum areal capacity of 5.60 mAh cm−2 is attained at a sulfur loading of ~4.0 mg cm−2, meeting the requirements for high-energy-density batteries.