Research initiatives in sodium and potassium ion batteries have gained great impetus in the last decade due to its better sustainability quotient compared to the more popular lithium-ion battery technology. However, the larger and heavier sodium and potassium ions, leads to a loss in energy density and hence efforts are being made to reduce the proportion of inactive material from the fabricated electrode. Self supporting electrodes leads to the elimination of copper or aluminium based current collectors as well as electrochemically inactive binders and helps in improving the overall energy density of the battery. Also, flexible self supporting electrodes can play a pivotal role in next generation wearable electronic and artificial intelligence based devices. Carbon nanotubes (CNTs) have been established as superior conducting components for battery electrodes due to its robust mechanical and electrical properties. Various composites with CNT have been studied as electrode material for lithium, sodium and potassium ion batteries. However, most of the work reported is concentrated on improving the conductivity of the slurry based electrode material with composite formation using CNT. This review focusses on the studies reported on self supporting CNT film and its composites for application as anodes in sodium and potassium ion battery. These self supporting CNT based anodes act as current collector and also contribute in storage of the K+/Na+ ions during the charging process. The highly conductive CNT network eliminates the need for binders and current collectors, reducing inactive components and enhancing energy density. Their high surface area and tunable porosity enable efficient ion transport and provide mechanical resilience against severe volume fluctuations associated with the insertion/extraction of large Na+ and K+ ions. However, the relatively low reversible capacity of pristine CNTs, limited intercalation sites and sluggish diffusion kinetics for larger alkali ions remain critical issues. In addition, achieving stable electrode-electrolyte interfaces and suppressing continuous solid electrolyte interphase (SEI) formation pose long term cycling challenges. Large scale synthesis of defect-engineered, heteroatom doped, or hybrid CNT based self-supporting architectures at low cost is also a major bottleneck. Here, the progress made in improving the electrochemical properties of these CNT based self supporting anodes has been critically reviewed and the prospects and challenges ahead has been elaborated to facilitate further development in this field.

Prospects and challenges of self-supporting CNT based anodes for sodium and potassium ion batteries

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发表日期：

2026年4月2日

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Bristisnata Kashyap,
Dimple P Dutta

摘要

Research initiatives in sodium and potassium ion batteries have gained great impetus in the last decade due to its better sustainability quotient compared to the more popular lithium-ion battery technology. However, the larger and heavier sodium and potassium ions, leads to a loss in energy density and hence efforts are being made to reduce the proportion of inactive material from the fabricated electrode. Self supporting electrodes leads to the elimination of copper or aluminium based current collectors as well as electrochemically inactive binders and helps in improving the overall energy density of the battery. Also, flexible self supporting electrodes can play a pivotal role in next generation wearable electronic and artificial intelligence based devices. Carbon nanotubes (CNTs) have been established as superior conducting components for battery electrodes due to its robust mechanical and electrical properties. Various composites with CNT have been studied as electrode material for lithium, sodium and potassium ion batteries. However, most of the work reported is concentrated on improving the conductivity of the slurry based electrode material with composite formation using CNT. This review focusses on the studies reported on self supporting CNT film and its composites for application as anodes in sodium and potassium ion battery. These self supporting CNT based anodes act as current collector and also contribute in storage of the K⁺/Na⁺ ions during the charging process. The highly conductive CNT network eliminates the need for binders and current collectors, reducing inactive components and enhancing energy density. Their high surface area and tunable porosity enable efficient ion transport and provide mechanical resilience against severe volume fluctuations associated with the insertion/extraction of large Na⁺ and K⁺ ions. However, the relatively low reversible capacity of pristine CNTs, limited intercalation sites and sluggish diffusion kinetics for larger alkali ions remain critical issues. In addition, achieving stable electrode-electrolyte interfaces and suppressing continuous solid electrolyte interphase (SEI) formation pose long term cycling challenges. Large scale synthesis of defect-engineered, heteroatom doped, or hybrid CNT based self-supporting architectures at low cost is also a major bottleneck. Here, the progress made in improving the electrochemical properties of these CNT based self supporting anodes has been critically reviewed and the prospects and challenges ahead has been elaborated to facilitate further development in this field.