An Iron-Air Battery from Abundant Materials for Household and Village Electricity Storage: A First-Principles Design and Cost Test

Design and first-principles cost test of an alkaline iron-air stationary battery (iron, air, water, potassium hydroxide) at 10 kWh household and 100 kWh village scale. SIMULATED, NOT MEASURED; nothing was built or hardware-tested. Round-trip efficiency is 58.6 percent (1.05 V discharge, 1.65 V charge, 92 percent coulombic efficiency). At 10-hour duration, delivered energy costs $0.240/kWh (household) and $0.158/kWh (village) under daily cycling, versus $0.194/$0.153 for lithium iron phosphate and $0.513/$0.420 for lead-acid. Extended to 48 hours, the household design costs $4,766 to build and delivers energy at $0.104/kWh at 150 cycles per year, beating both baselines; it beats lead-acid at every duty tested and loses to lithium wherever charging energy is priced.