Lithium ion battery and negative electrode composite electrode plate thereof

Abstract

The invention discloses a lithium ion battery and a negative electrode composite electrode plate thereof. A preparation method for the negative electrode composite electrode plate comprises the steps of 1) preparing a solution A; 2) preparing a material B; and 3) preparing a silicon / titanium dioxide / carbon composite electrode plate. According to the prepared composite negative electrode plate, based on the zero-strain characteristic of the titanium dioxide material and a relatively high voltage platform, the expansion rate of the material in a charging-discharging process is lowered and the safety performance of the battery is improved; meanwhile, by virtue of a TiO<2> / C coating layer, the electrical conductivity of the composite material is improved, and volume change in a silicon cycling process can be effectively suppressed by virtue of a porous structure; in addition, TiO<2> / C, used as framework support, can provide a three-dimensional space transmission channel for lithium ion transfer; meanwhile, the negative electrode plate can be directly used without requiring a binder and a conductive agent; and the prepared composite negative electrode plate has the characteristics of high gram volume, excellent rate capability and strong liquid absorption and retention capability and the like, so that requirement of the high-specific-energy-density battery on the negative electrode material can be satisfied particularly.

Description

technical field

[0001] The invention belongs to the field of preparation of lithium-ion battery materials, in particular to a lithium-ion battery negative electrode composite pole piece and the lithium-ion battery. Background technique

[0002] Silicon carbon negative electrode material is a new type of negative electrode material developed in recent years, and it is used in high specific energy batteries due to its high capacity and other characteristics. However, during the use of silicon carbon negative electrode materials, pure silicon materials will not There is a huge volume change in the battery, which will lead to the pulverization of the prepared pole piece, causing the active material to fall off from the negative electrode plate, causing the separation of the electrode active material and the current collector, thereby seriously affecting the cycle performance of the battery; At the same time, the silicon material is very easy to agglomerate, resulting in poor cyc...

Images