The invention belongs to the technical field of materials, and particularly relates to a modified organic
silicon polymer, a preparation method thereof and a
lithium secondary battery. The preparationmethod comprises the following steps: carrying out a
hydrosilylation reaction on side-chain
hydrogen-containing
silicone oil and a modifier under the action of a catalyst, and
grafting amino, alkoxyor carboxyl functional groups on the modifier onto the
hydrogen-containing
silicone oil through the reaction to obtain the modified
organosilicon polymer. The obtained modified organic
silicon polymeris an
elastomer containing amino, alkoxy or carboxyl functional groups on a
side chain, not only has good bonding performance and self-healing performance, but also can interact with functional groups such as hydroxyl on the surface of a
silicon-based negative
electrode to form a self-healing three-dimensional cross-linked network, effectively inhibits the
volume expansion effect of the silicon-based negative
electrode active material, and maintains the integrity of the silicon-based negative
electrode structure in the charging and discharging process, so that the
cycling stability of the obtained
lithium secondary battery is improved.