Organoboron-thiophene-based polymer electrodes for high-performance lithium-ion batteries.

Polymer electrodes are drawing widespread attention to the future generation of lithium-ion battery materials. However, weak electrochemical performance of organic anode materials still exists, such as low capacity, low rate performance, and low cyclability. Herein, we successfully constructed a donor-acceptor thiophene-based polymer (PBT-1) by introducing an organoboron unit. The charge delocalization and lower LUMO energy level due to the unique structure enabled good performance in electrochemical tests with a reversible capacity of 405 mA h g at 0.5 A g and over 10 000 cycles at 1 A g. Moreover, electron paramagnetic resonance (EPR) spectra revealed that the unique stable spin system in the PBT-1 backbone during cycling provides a fundamental explanation for the highly stable electrochemical performance. This work offers a reliable reference for the design of organic anode materials and expands the potential application directions of organoboron chemistry.