{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T19:44:56Z","timestamp":1792784696812,"version":"4.5.0"},"reference-count":32,"publisher":"American Chemical Society (ACS)","issue":"38","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/100009088","name":"Nippon Sheet Glass Foundation for Materials Science and Engineering","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100009088","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Japan Research Institute of Industrial Science","id":[{"id":"https:\/\/ror.org\/03zqd3v71","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,28]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>F\u2013-conducting apatites have unique structural features and thus have emerged as promising electrolytes for next-generation all-solid-state fluoride-ion batteries (FIBs). Structural and morphological analyses indicate that OH\u2013 in Ca10\u2013x(HPO4)x(PO4)6\u2013x(OH)2\u2013x (x = 0, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5, and 0.6) are exchanged with F\u2013 via chemical fluorination at 150 \u00b0C using XeF2. We investigate the F\u2013 conductivity of Ca10\u2013x(HPO4)x(PO4)6\u2013xF2\u2013x synthesized with various x values. AC impedance spectroscopy reveals a large increase in ionic conductivity, reaching 5 \u00d7 10\u20135 S cm\u20131 at 80 \u00b0C, with a low activation energy of 0.15 eV for x = 0.3. The material is chemically stable at least up to 1200 \u00b0C. Due to the robust crystalline framework containing Ca, the electrochemical stability window (ESW) expands in the active direction, and an extremely high ESW of over 5 V is achieved. Although further increasing the ionic conductivity of this material remains a challenge, its excellent ESW is a unique advantage over existing solid electrolytes in next-generation FIBs, in which safety is a priority during high-voltage operation and in harsh environments.<\/jats:p>","DOI":"10.1021\/acs.inorgchem.6c03355","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T10:02:15Z","timestamp":1789639335000},"page":"22601-22606","source":"Crossref","is-referenced-by-count":0,"title":["Fluoride-Ion\nConduction and Wide Electrochemical Stability\nWindow for Ca10\u2013\n                    <i>x<\/i>\n                    (HPO4)\n                    <i>x<\/i>\n                    (PO4)6\u2013\n                    <i>x<\/i>\n                    F2\u2013\n                    <i>x<\/i>\n                    (0 \u2264\n                    <i>x<\/i>\n                    \u2264 0.6)"],"prefix":"10.1021","volume":"65","author":[{"given":"Kodai","family":"Fukuda","sequence":"first","affiliation":[{"name":"Shiraishi Central Laboratories Co., Ltd. , 4-78 Motohama-Cho , , ,","place":["Amagasaki, Hyogo, Japan, 660-0085"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shota","family":"Umemoto","sequence":"additional","affiliation":[{"name":"Shiraishi Central Laboratories Co., Ltd. , 4-78 Motohama-Cho , , ,","place":["Amagasaki, Hyogo, Japan, 660-0085"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kenichiro","family":"Eguchi","sequence":"additional","affiliation":[{"name":"Shiraishi Kogyo Kaisha, Ltd. , 2-7, Nakanoshima 2-Chome , , ,","place":["Kita-ku, Osaka, Japan, 530-0005"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0490-2760","authenticated-orcid":true,"given":"Tsuyoshi","family":"Takami","sequence":"additional","affiliation":[{"name":"Otemon Gakuin University , , 2-1-15 Nishiai , , ,","place":["Ibaraki City, Osaka, Japan, 567-8502"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"issue":"4","key":"2026092809213829200_cit1","doi-asserted-by":"publisher","first-page":"369","DOI":"10.1016\/0013-4686(78)80076-0","article-title":"Electrical\nproperties of hydroxyapatite","volume":"23","author":"Yamamoto","year":"1978","journal-title":"Electrochim. Acta"},{"issue":"10","key":"2026092809213829200_cit2","doi-asserted-by":"publisher","first-page":"5180","DOI":"10.1021\/jp412771f","article-title":"Diffusion path and\nconduction mechanism of protons\nin hydroxyapatite","volume":"118","author":"Yashima","year":"2014","journal-title":"J. Phys. Chem. C"},{"key":"2026092809213829200_cit3","doi-asserted-by":"publisher","DOI":"10.1038\/s43246-026-01172-3","article-title":"Reversible phase\ntransition of indium hydroxide for giant mechanical energy storage","volume":"7","author":"Sun","year":"2026","journal-title":"Commun. Mater."},{"key":"2026092809213829200_cit4","doi-asserted-by":"publisher","first-page":"100","DOI":"10.1016\/j.matlet.2012.12.074","article-title":"Enhanced ionic\nconduction\nin hydroxyapatites","volume":"95","author":"Singh","year":"2013","journal-title":"Mater. Lett."},{"key":"2026092809213829200_cit5","doi-asserted-by":"publisher","DOI":"10.1016\/j.mtcomm.2022.103360","article-title":"Study of microstructural\nand electrical properties\nof silver substituted hydroxyapatite for drug delivery applications","volume":"31","author":"Chatterjee","year":"2022","journal-title":"Mater. Today Commun."},{"key":"2026092809213829200_cit6","doi-asserted-by":"publisher","DOI":"10.1016\/j.mseb.2022.115786","article-title":"Synthesis and ionic conductivity\nof phosphate-sulfate fluorapatites Ca10-xNax(PO4)6-x(SO4)xF2 (x = 0, 3, 6)","volume":"282","author":"Nouri","year":"2022","journal-title":"Mater.\nSci. Eng. B"},{"key":"2026092809213829200_cit7","doi-asserted-by":"publisher","first-page":"389","DOI":"10.1007\/BF02374158","article-title":"Synthesis\nand ionic conduction of apatite-type materials","volume":"6","author":"Tao","year":"2000","journal-title":"Ionics"},{"key":"2026092809213829200_cit8","doi-asserted-by":"publisher","first-page":"611","DOI":"10.1007\/s12034-006-0012-3","article-title":"Synthesis of nanocrystalline fluorinated\nhydroxyapatite by microwave processing and its in vitro dissolution\nstudy","volume":"29","author":"Rameshbabu","year":"2006","journal-title":"Bull. Mater. Sci."},{"issue":"4","key":"2026092809213829200_cit9","doi-asserted-by":"publisher","first-page":"949","DOI":"10.1039\/dt9810000949","article-title":"Influence of fluorine\nsubstitution on the proton conductivity\nof hydroxyapatite","volume":"6","author":"Maiti","year":"1981","journal-title":"J. Chem. 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Bull."},{"key":"2026092809213829200_cit13","doi-asserted-by":"publisher","first-page":"479","DOI":"10.4028\/www.scientific.net\/AMR.1-2.479","article-title":"Anionic conductivity\nin fluorapatites: correlation\nbetween structure and electrical properties","volume":"1\u20132","author":"Laghzizil","year":"1994","journal-title":"Adv. Mater. Res."},{"key":"2026092809213829200_cit14","doi-asserted-by":"publisher","DOI":"10.1088\/1361-648X\/accb32","article-title":"Challenges for fluoride\nsuperionic conductors: Fundamentals, design, and applications","volume":"35","author":"Takami","year":"2023","journal-title":"J. Phys.: Condens. Matter"},{"key":"2026092809213829200_cit15","doi-asserted-by":"publisher","DOI":"10.1016\/j.mtphys.2021.100523","article-title":"High fluoride-ion conductivity\nand fluoride-ion conductor\u2500insulator\ntransition in fluorinated hexagonal boron nitride","volume":"21","author":"Takami","year":"2021","journal-title":"Mater. 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Ionic conductivity\nof nonstoichiometric M1\u2013xRxF2+x and R1\u2013\u00a0yMyF3\u2013y crystals (M = Ca, Sr, Ba; R are rare earth elements)","volume":"59","author":"Sobolev","year":"2014","journal-title":"Crystallogr. Rep."},{"issue":"3","key":"2026092809213829200_cit27","doi-asserted-by":"publisher","first-page":"190","DOI":"10.1179\/143307511X13018917925711","article-title":"Synthesis, characterisation and thermal\nproperties of Ca5(PO4)3(OH)1\u2013xFx (0\u2a7dx\u2a7d1) nanopowders\nvia pH cycling method","volume":"15","author":"Eslami","year":"2011","journal-title":"Mater. Res. Innovations"},{"issue":"15","key":"2026092809213829200_cit28","doi-asserted-by":"publisher","first-page":"3865","DOI":"10.1039\/B203114K","article-title":"Density functional theory calculations of local ordering\nof hydroxy groups and fluoride ions in hydroxyapatite","volume":"4","author":"de Leeuw","year":"2002","journal-title":"Phys. Chem. Chem. Phys."},{"key":"2026092809213829200_cit29","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.70.155104","article-title":"Electronic structure and bonding\nin calcium apatite crystals: Hydroxyapatite, fluorapatite, chlorapatite,\nand bromapatite","volume":"70","author":"Rulis","year":"2004","journal-title":"Phys. Rev. B"},{"key":"2026092809213829200_cit30","doi-asserted-by":"publisher","DOI":"10.1002\/aenm.202204098","article-title":"Electronic\nconductivity of lithium\nsolid electrolytes","volume":"13","author":"Shao","year":"2023","journal-title":"Adv. Energy Mater."},{"key":"2026092809213829200_cit31","doi-asserted-by":"publisher","DOI":"10.1016\/j.ssi.2024.116511","article-title":"Enhancement\nof ionic conductivity\nand electrochemical stability of PVA\/HPMC\/PANI\/CuSO4 gel\npolymer for rechargeable batteries electrolytes","volume":"408","author":"Mahmood","year":"2024","journal-title":"Solid State Ionics"},{"key":"2026092809213829200_cit32","doi-asserted-by":"publisher","DOI":"10.1016\/j.chphi.2024.100778","article-title":"Enhancing ionic conductivity, mechanical\nstability\nand electrochemical properties simultaneously by integrating POSS-PEG13.3 hybrid nanoparticles into PEO-NaClO4 solid\npolymer electrolytes","volume":"10","author":"Polu","year":"2025","journal-title":"Chem. Phys. Impact"}],"container-title":["Inorganic Chemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acs.inorgchem.6c03355","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/inocaj\/article-pdf\/65\/38\/22601\/68540514\/acs.inorgchem.6c03355.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/inocaj\/article-pdf\/65\/38\/22601\/68540514\/acs.inorgchem.6c03355.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T13:35:27Z","timestamp":1790602527000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/inocaj\/article\/65\/38\/22601\/5431836\/Fluoride-Ion-Conduction-and-Wide-Electrochemical"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":32,"journal-issue":{"issue":"38","published-online":{"date-parts":[[2026,9,17]]},"published-print":{"date-parts":[[2026,9,28]]}},"URL":"https:\/\/doi.org\/10.1021\/acs.inorgchem.6c03355","relation":{},"ISSN":["0020-1669","1520-510X"],"issn-type":[{"value":"0020-1669","type":"print"},{"value":"1520-510X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]}}}