Doping-Engineered Praseodymium–Barium Cobaltite Oxides for Dual Oxygen and Lithium Ionic Diffusivity in Offshore Metal–Air Batteries

This research conducts comprehensive molecular dynamics simulations on doped double perovskites, PrBa(1-x)A'xCo(2-y)B'yO5+δ (0 ≤ x ≤ 0.25, 0 ≤ y ≤ 0.25, and 0.375≤ δ ≤0.500), as catalyst in metal–air batteries to systematically evaluate various doping strategies and identify the most effective approach for enhancing ionic diffusion. In addition, the application of metal–air batteries and their modifications for offshore power plants have been addressed. Four types of doping were studied: (i) substitution at Ba²⁺ sites with Sr²⁺, Ca²⁺, or Na⁺; (ii) substitution at Co³⁺ sites with Fe³⁺, Cr³⁺, Mn³⁺, Ni³⁺, Al³⁺, or Zn²⁺; (iii) dual-site doping with Na⁺ and Zn²⁺ at Ba²⁺ and Co³⁺ sites, respectively; and (iv) interstitial doping with Li⁺ ions. Among single-site dopants, Na⁺ at the Ba-site and Zn2+ at the Co-site, as well as dual-site–doped PrBa0.875Na0.125Co1.875Zn0.125O5.375, exhibit better oxygen ion mobility. In contrast, interstitial Li+ doping in Li0.125-doped PrBa0.9375Co2O5.5 provides better oxygen diffusivity, comparable to other samples, and additionally enables significant Li+ mobility. Li0.125-doped PrBa0.9375Co2O5.5, with dual oxygen-lithium diffusivity roles, needs to be combined with doped porous carbon materials and metal oxides as a matrix, and transition metal oxide catalysts coated with bio-inspired oxygen-selective-membrane to guarantee operation in offshore environments with high humidity.