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{"title":"Ab Initio Study of Phosphorus Anodes for Lithium-nand Sodium-Ion Batteries","authors":"Martin Mayo (2573863), Kent J. Griffith (1598332), ChrisJ. Pickard (2524567), Andrew J. Morris (206326)","doi":"10.1021/acs.chemmater.5b04208.s021","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5b04208.s021","url":null,"abstract":"Phosphorusnhas received recent attention in the context of high-capacitynand high-rate anodes for lithium- and sodium-ion batteries. Here,nwe present a first-principles structure prediction study combinednwith NMR calculations, which gives us insights into its lithiation/sodiationnprocess. We report a variety of new phases found by the ab initionrandom structure searching (AIRSS) and the atomic species swappingnmethods. Of particular interest, a stable Na<sub>5</sub>P<sub>4</sub>–<i>C</i>2/<i>m</i> structure and locallynstable structures found less than 10 meV/f.u. from the convex hullnsuch as Li<sub>4</sub>P<sub>3</sub>–<i>P</i>2<sub>1</sub>2<sub>1</sub>2<sub>1</sub>, NaP<sub>5</sub>–<i>Pnma</i>, and Na<sub>4</sub>P<sub>3</sub>–<i>Cmcm</i>. The mechanical stability of Na<sub>5</sub>P<sub>4</sub>–<i>C</i>2/<i>m</i> and Li<sub>4</sub>P<sub>3</sub>–<i>P</i>2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> has been studiednby first-principles phonon calculations. We have calculated averagenvoltages, which suggest that black phosphorus (BP) can be considerednas a safe anode in lithium-ion batteries due to its high lithium insertionnvoltage, 1.5 V; moreover, BP exhibits a relatively low theoreticalnvolume expansion compared with other intercalation anodes, 216% (Δ<i>V</i>/<i>V</i>). We identify that specific rangesnin the calculated shielding can be associated with specific ionicnarrangements, results that play an important role in the interpretationnof NMR spectroscopy experiments. Since the lithium-phosphides arenfound to be insulating even at high lithium concentrations, we shownthat Li–P-doped phases with aluminum have electronic statesnat the Fermi level suggesting that using aluminum as a dopant cannimprove the electrochemical performance of P anodes.","PeriodicalId":522381,"journal":{"name":"Figshare","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147896105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}