ELECTRONICALLY CONDUCTIVE POLYMER BINDER FOR LITHIUM-ION BATTERY ELECTRODE

摘要

A family of carboxylic acid group containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

主权项

1. A polymeric composition with repeating units of the formula:wherein 0<=x, x′, y and z<=1, x+x′+y+z=1, R1 and R2 is (CH2)nCH3 where n=0-8, R3 and R4 is (CH2)nCOOH where n=0-8, and R5 and R6 is any combination of H, COOH and COOCH3.