A specially designed Li–H₂O₂ semi-fuel cell based on hybrid electrolytes is proposed. It is a combination of fuel cell and lithium battery. Five “mechanical charge–discharge” cycles (800 hours in total) of the Li–H₂O₂ semi-fuel cell were conducted. The cell exhibits fast mechanical rechargeability, good stability and high lithium utilization. Output power of the Li–H₂O₂ semi-fuel cell can be flexibly adjusted by changing H₂O₂ concentration.