Secondary battery pack with improved thermal management

A process for preparation of a secondary battery pack comprising

• at least one battery module casing 102 in which is disposed a plurality of battery cells 103 which are electrically connected to one another,
• a silicone rubber syntactic foam comprising a silicone rubber binder and hollow glass beads, and said silicone rubber syntactic foam fills partially or fully the open space of said battery module casing 102 and/or covering partially or totally said battery cells 103 and/or covering partially or totally said module casing 102, and
• optionally a lid covering the battery module casing 102;
• and
• wherein said silicone rubber syntactic foam is obtained by curing an addition curing type organopolysiloxane composition X, the process comprising
• a) preparing at least one battery module casing 102 in which is disposed a plurality of battery cells 103 which are electrically connected to one another,
• b) introducing into the said battery module casing 102 the addition curing type organopolysiloxane composition X,
• c) filling completely or partially said battery module casing 102, and
• d) allowing the curing to occur so as to form a silicone rubber syntactic foam comprising a silicone rubber binder and hollow glass beads, and optionally
• e) covering the battery module casing 102 with a lid
• f) feeding into a base feed line a liquid silicone base MS1 comprising:
• i) at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, said alkenyl groups each containing from 2 to 14 carbon atoms, preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and most preferably said alkenyl groups are vinyl groups,
• ii) hollow glass beads D, and preferably hollow borosilicate glass microspheres D1,
• iii) at least one silicon compound B having at least two and preferably at least three hydrogen atoms bonded to silicon per molecule, and
• iv) optionally a cure rate controller G which slows the curing rate,
• g) feeding into a catalyst feed line a catalyst master batch MC comprising:
• i) at least one hydrosilylation catalyst C;
• and
• ii) optionally, at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, said alkenyl groups each containing from 2 to 14 carbon atoms, preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and most preferably said alkenyl groups are vinyl groups;
• h) feeding into an inhibitor feed line an inhibitor master batch MI comprising:
• i) a cure rate controller G which slows the curing rate;
• and
• ii) optionally, at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, said alkenyl groups each containing from 2 to 14 carbon atoms, preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and most preferably said alkenyl groups are vinyl groups;
• and
• i) optionally feeding into an additive feed line an additive masterbatch MA comprising:
• i) at least one additive H such as a pigment, a dye, clays, a surfactant, hydrogenated castor oil, wollastonite, aluminium trihydrate, magnesium hydroxide, halloysite, huntite, hydromagnesite, expandable graphite, zinc borate, mica or a fumed silica, and
• ii) optionally at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, said alkenyl groups each containing from 2 to 14 carbon atoms, preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and most preferably said alkenyl groups are vinyl groups;
• and
• j) directing said liquid silicone base MS1, said catalyst master batch MC and said inhibitor master batch MI and optionally said additive masterbatch MA into a tank to obtain the addition curing type organopolysiloxane composition X.