Studies of Co, Al, and Mn substitutions in NdNi5 metal hydride alloys

► A guideline of Co, Mn, and Al-contents for NiMH battery was established. ► Nd-AB5 shows improvement in high-rate discharge property comparing to regular AB5. ► A composition of Nd17Co8Al6Mn8Ni61 was identified with general excellent properties. ► Different from regular AB5, the un-annealed Nd-AB5 alloys contain secondary phase.