The circulation properties and microstructure in active substances for MH/Ni batteries have been researched. It was found that corresponding relationship among attenuation of circulation property and decreasing of lattice parameters, average grain size, micro-strain, total fault probability in β-Ni(OH)₂ with increasing of circulation cycles and producing and increasing of corrosive products (A(OH)₃ and B phases) in AB₅ with increasing of circulation cycles. Attenuation mechanics of circulation properties for MH/Ni battery has been discussed. Circulation properties attenuation is the synthesized results of obvious changes of crystal structure and microstructure in positive and negative electrode materials during circulation cycle experiment, especially corrosion products are separated out in AB₅ materials, which deteriorating electrochemical properties of β-Ni(OH)₂ and AB₅ materials and which depleting and deteriorating electrolyte at the same times. For elevating circulation property of this battery some additives of positive electrode were used. The research results show that effects of CaF₂ and Lu₂O₃ are better. Specially the effect of CaF₂ is the best, so it has broad practicability.

Key words: MH/Ni battery, circulation properties, microstructure, positive electrode additives, X-ray diffraction