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1. Ab initio determination of a simultaneous dual-ion charging mechanism for Ni _0.25 Mn _0.75 O ₂ through redox reactions of Ni ²⁺ /Ni ⁴⁺ and O ^2- /O ^-

   https://doi.org/10.1039/D2TA03938A  

   Shepard, Robert; Brennan, Scott; Juran, Taylor R; Young, Joshua; Smeu, Manuel (July 2022, Journal of Materials Chemistry A)

   Over recent years, great efforts have been made to push the limits of layered transition metal oxides for secondary battery cathodes. This is particularly true for overall capacity, which has reached a terminal theoretical value for many materials. One avenue for increasing this capacity during charging is the intercalation of anions post cation deintercalation. This work investigates the charging mechanism of the P3-Na0.5Ni0.25 Mn0.75O2 cathode material through cation (Na) deintercalation and anion (ClO4) intercalation by means of density functional theory. The calculations corroborate experimental findings of increased capacity (135 mAh g-1 to 180 mAh g-1) through the intercalation of anions. However, this work demonstrates that a process of simultaneous cation deintercalation/anion intercalation is the primary charging mechanism, with charge compensation reactions of Ni2+/Ni4+ and O2-/O- occurring within the cathode material. To elucidate this simultaneous process, a novel method for computationally determining anion voltage in which one must consider full electrolyte interactions is proposed. Based on the results, it is believed that a simultaneous cation deintercalation/anion intercalation mechanism provides one potential avenue for the discovery of the next generation of secondary batteries. 

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2. Generation of a Ni ₃ Phosphinidene Cluster from the Ni(0) Synthon, Ni(η ³ -CPh ₃ ) ₂

   https://doi.org/10.1021/acs.organomet.0c00095  

   Touchton, Alexander J.; Wu, Guang; Hayton, Trevor W. (April 2020, Organometallics)
3. First Structurally Characterized Tricyanomanganate(III) and its Magnetic {Mn ^III ₂ M ^II ₂ } Complexes (M ^II = Mn, Ni)

   https://doi.org/10.1021/ic1006605  

   Tang, Minao; Li, Dongfeng; Mallik, Uma Prasad; Withers, Jeffrey R.; Brauer, Shari; Rhodes, Michael R.; Clérac, Rodolphe; Yee, Gordon T.; Whangbo, Myung-Hwan; Holmes, Stephen M. (June 2010, Inorganic Chemistry)
4. Generation and Reactivity of a Ni ^III ₂ (μ-1,2-peroxo) Complex

   https://doi.org/10.1021/jacs.0c10958  

   Zhao, Norman; Filatov, Alexander S.; Xie, Jiaze; Hill, Ethan A.; Rogachev, Andrey Yu.; Anderson, John S. (December 2020, Journal of the American Chemical Society)

   null (Ed.)
5. Insertion of CO ₂ Mediated by a (Xantphos)Ni ^I –Alkyl Species

   https://doi.org/10.1002/anie.201906005  

   Diccianni, Justin B.; Hu, Chunhua T.; Diao, Tianning (August 2019, Angewandte Chemie International Edition)

   Abstract The incorporation of CO₂into organometallic and organic molecules represents a sustainable way to prepare carboxylates. The mechanism of reductive carboxylation of alkyl halides has been proposed to proceed through the reduction of Ni^IIto Ni^Iby either Zn or Mn, followed by CO₂insertion into Ni^I‐alkyl species. No experimental evidence has been previously established to support the two proposed steps. Demonstrated herein is that the direct reduction of (tBu‐Xantphos)Ni^IIBr₂by Zn affords Ni^Ispecies. (tBu‐Xantphos)Ni^I‐Me and (tBu‐Xantphos)Ni^I‐Et complexes undergo fast insertion of CO₂at 22 °C. The substantially faster rate, relative to that of Ni^IIcomplexes, serves as the long‐sought‐after experimental support for the proposed mechanisms of Ni‐catalyzed carboxylation reactions. 

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