Conjugated Nitroxide Radical Polymer with Low Temperature Tolerance Potential for High-Performance Organic Polymer...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Low-temperature operation significantly degrades the performance of commercial rechargeable lithium-ion batteries (LIBs).
• Organic polymer electrode materials offer a promising alternative due to their nonintercalation redox mechanisms, potentially overcoming low-temperature limitations.

Purpose of the Study:

• To synthesize and characterize a novel radical polymer, P(DATPAPO-TPA), for enhanced LIB performance, particularly at low temperatures.
• To investigate the structural features of P(DATPAPO-TPA) that contribute to its electrochemical properties and ion transport.

Main Methods:

• Synthesis of a conjugated nitrogen-rich triphenylamine-based radical polymer (P(DATPAPO-TPA)) with nitroxide pendants.
• Electrochemical characterization, including discharge capacity, charge-discharge plateau analysis, cycling stability, and rate capability testing.
• Evaluation of performance at low temperatures (0 °C).

Main Results:

• P(DATPAPO-TPA) exhibited a notable discharge capacity of 143.3 mA h·g^-1 at a high plateau of ~3.75 V vs Li⁺/Li.
• The polymer demonstrated excellent cyclability with 83.1% capacity retention after 2000 cycles at 50 C.
• Remarkable low-temperature performance was observed, maintaining 139.2 mA h·g^-1 at 0 °C.

Conclusions:

• The P(DATPAPO-TPA) radical polymer shows superior electrochemical performance and stability, outperforming many existing radical polymer cathodes.
• Its unique structural design facilitates effective ion transport, leading to excellent rate capability and cyclability.
• P(DATPAPO-TPA) represents a viable strategy for developing advanced electrode materials for low-temperature LIB applications.