{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T16:53:59Z","timestamp":1787072039246,"version":"build-2736575974"},"reference-count":59,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22371287"],"award-info":[{"award-number":["22371287"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["22371287"],"award-info":[{"award-number":["22371287"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Copper selenide compounds, owing to their excellent electrical transport properties and low thermal conductivity, are promising thermoelectric materials, but their poor mechanical flexibility limits practical applications in flexible devices. Herein, a simple all-electrochemical strategy was developed to fabricate polypyrrole (PPy)\/Cu2\u2212xSe composite thermoelectric films through sequential electropolymerization of pyrrole and electrodeposition of Cu2\u2212xSe. By optimizing the deposition potential of Cu2\u2212xSe and pyrrole polymerization time, the thermoelectric performance of the composite films was significantly enhanced. The optimized PPy\/Cu2\u2212xSe composite film achieved a maximum power factor of 174.05 \u00b1 9.87 \u03bcW m\u22121 K\u22122, nearly 300 times higher than that of pristine PPy, while maintaining a low thermal conductivity of 0.30 W m\u22121 K\u22121. The composite film also exhibited excellent flexibility, retaining 94.77% of its initial power factor after 1000 bending cycles. A flexible thermoelectric device assembled from the composite films delivered a maximum output power of 240.5 nW at \u0394T = 50 K. This work provides an effective strategy for developing Cu2\u2212xSe-based flexible thermoelectric composites.<\/jats:p>","DOI":"10.3390\/ma19163496","type":"journal-article","created":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T16:12:11Z","timestamp":1787069531000},"page":"3496","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Electrochemical Synthesis of Polypyrrole\/Cu2\u2212xSe Composites for Enhanced Thermoelectric Performance"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-8752-5397","authenticated-orcid":false,"given":"Yunfei","family":"Cai","sequence":"first","affiliation":[{"name":"School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 101408, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caiyan","family":"Gao","sequence":"additional","affiliation":[{"name":"Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4000-8141","authenticated-orcid":false,"given":"Cun-Yue","family":"Guo","sequence":"additional","affiliation":[{"name":"School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 101408, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"100027","DOI":"10.1016\/j.cnt.2026.100027","article-title":"System-level design framework of wearable thermoelectric generators for real-world applications: Integrating device architecture, thermal management, and human comfort","volume":"2","author":"Pan","year":"2026","journal-title":"Carbon Neutr. 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