Abstract
Ionic thermoelectric (i-TE) have become promising candidate for harvesting low-grade thermal energy. However, the development of n-type i-TE materials still lag far behind their p-type counterparts, which impedes the application. Herein, engineering a liquid crystal elastomer (LCE) from side-chain to main-chain structure, just swollen with single LiBF4 or EMIM TFSI, enables the largest adjustable p-n (28.8 ~ −27.4 mV K−1) span among current homologous materials below 30% RH. These high n- and p-type performance further ensure the successful integration of a homogeneous π-type fiber-shaped i-TE capacitor, where three p/n pairs yield an output voltage of 402.5 mV under a tiny temperature difference of 2.5 K. The areal energy density of per n-type fiber reaches 8.1 mJ m−2. More importantly, the i-TE materials also exhibit excellent stability under loadings of cyclic stretching, long-term testing, or temperature-controlled cycling, highlighting its potential for efficient thermal-charge energy storage in flexible electronics and smart wearables.
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The authors declare that the data supporting the findings of this study are available within the paper and its supplementary information files, and all data are available from the corresponding author upon request.
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Acknowledgments
This work was supported by the National Natural Science Foundation of China (U23A20685, U24A2061, 52403349), the Innovation Program of Shanghai Municipal Education Commission (202101070003E00110), Shanghai Committee of Science and Technology (23520710300, 24YF2700400), AI-Enhanced Research Program of Shanghai Municipal Education Commission (SMEC-AI-DHUY-04), and the Fundamental Research Funds for the Central Universities (2232024D-32). We acknowledge the technicians at Shenzhen HUASUAN Technology Co., Ltd. for assistance with theoretical calculations.
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L.W., W.J., and T.S. conceived the ideas and designed the work. L.C. carried out the experiments, including material preparation and characterization, device fabrication, and measurements. L.C. and T.S. contributed to microstructural characterization. T.S. carried out the density functional theory and molecular dynamics calculations. L.C. assisted with the power-generation measurements. T.S. contributed to the drawings. L.C. and T.S. wrote the draft. H.Z. and L.C. contributed to the discussion and editing. All authors approve the final version of the manuscript.
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Cao, L., Sun, T., Zhao, H. et al. Engineering liquid crystal elastomer unlocks high thermopower for fiber-shaped ionic thermoelectric capacitors. Nat Commun (2025). https://doi.org/10.1038/s41467-025-68011-w
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DOI: https://doi.org/10.1038/s41467-025-68011-w
