Tämä LSD ominaisuus tulee negatiivisen elektrodin (metallihydridielektrodi) materiaali muutoksista. Käytännössä tältä metallihydridielektrodilta "karkaa" vetyä ja tämä reagoi positiivisen Ni elektrodin kanssa muodostaen vettä, sama ilmiö tapahtuu myös ylilatauksessa. Artikkeli aiheesta:
http://www.electrochem.org/meetings/...s/216/0268.pdf
Lainaus:
Recently, a new type of Ni-MH batteries with lower
self-discharge than conventional ones has been attracting
more attention from a viewpoint of environmental
consciousness and usability. Newly developed RE-Mg-Ni
(RE: Rare earths) super-lattice hydrogen absorbing alloys
play an important role in these Ni-MH batteries. One of
the features of the new alloys is that they can sustain their
long-term cycleability without containing Co or Mn that
is considered as an essential element for conventional RENi
alloys with CaCu5 structure
Tässä vähän tästä itsepurkauksesta:
http://www.cpfreviews.com/Batteries-...een-Online.php
Lainaus:
The main cause of high self discharge rate for conventional NiMH Battery is mainly because of the positive electrode reduction reaction due to dissolved negative electrode material, decomposition of the positive electrode and "shuttle effect" of nitrogenous compounds. Researchers at Sanyo found out that the self discharge mechanisms can be significantly suppressed by using a super lattice Hydrogen absorbing alloy that is free from Co & Mn as a negative electrode and by improving the material used for separator. More improvements were achieved by change in electrolyte from KOH to NaOH rich electrolyte. All this gave birth to a totally new type of rechargeable NiMH batteries. Commonly called as low self discharge nickel-metal hydride i.e. LSD NiMH. Due to the low self discharge, cells are often marketed as pre-charged or ready to use rechargeable batteries.
Näköjään myös elektrolyytti on vaihdettu KOH->NaOH. NaOH on vähän "miedompi" lipeä eli ilmeisesti vaikuttaa elinikään.