Res. Chem. Intermed.
, Vol. 32, No. 5–6, pp. 419–429 (2006)
Also available online - www.vsppub.com
Inﬂuence of electroless nickel plating of
hydrogen-absorbing alloys on cycle characteristics of
nickel–metal hydride batteries
, YOSHIFUMI MAGARI, TADAYOSHI TANAKA,
HIROSHI NAKAMURA, TOSHIYUKI NOHMA and IKUO YONEZU
Mobile Energy Company, Sanyo Electric Co., Ltd., 7-3-2 Ibukidai-higashimachi, Nishi-ku, Kobe,
Hyogo, 651-2242, Japan
Received 22 October 2004; accepted 24 November 2004
Abstract—The effects of electroless nickel plating of a hydrogen-absorbing alloy on the cycle
characteristics of a nickel–metal hydride battery were investigated. The cycle life was improved by
employing an electroless nickel-plated hydrogen-absorbing alloy for the negative electrode, which
retained the same high-rate level and low-temperature characteristics compared to a cell using a non-
plated hydrogen-absorbing alloy. The electroless nickel-plated hydrogen-absorbing alloy provided
better electrochemical characteristics when its surface was partly and tightly covered by nickel
particles under optimal electroless plating conditions.
Keywords: Nickel–metal hydride battery; electroless nickel plating; hydrogen-absorbing alloy.
Nickel–metal hydride (Ni-MH) batteries, which have been widely used for such
applications as digital still cameras, notebook computers and power tolls, are still
being improved since they were marketed in 1990 . In addition, Ni-MH batteries
have been receiving much attention as a power source for Hybrid Electric Vehicles
(HEVs), which are considered as the most promising clean cars. Rechargeable
batteries are considered one of the most important components of HEVs because
their capability directly inﬂuences the driving and regenerating performance and
the life of HEVs. Since Ni-MH batteries have a better combination of output power,
capacity, life, reliability and cost, almost all commercialized HEVs employ Ni-MH
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