Anomalous manganese activation of a pyrophosphate cathode in sodium ion batteries: A combined experimental and theoretical study
Author | Park, Chan Sun |
Author | Kim, Heejin |
Author | Shakoor, Rana A. |
Author | Yang, Eunjeong |
Author | Lim, Soo Yeon |
Author | Kahraman, Ramazan |
Author | Jung, Yousung |
Author | Choi, Jang Wook |
Available date | 2022-10-05T07:23:08Z |
Publication Date | 2013 |
Publication Name | Journal of the American Chemical Society |
Resource | Scopus |
Abstract | Sodium ion batteries (SIBs) have many advantages such as the low price and abundance of sodium raw materials that are suitable for large-scale energy storage applications. Herein, we report an Mn-based pyrophosphate, Na2MnP2O7, as a new SIB cathode material. Unlike most Mn-based cathode materials, which suffer severely from sluggish kinetics, Na2MnP2O7 exhibits good electrochemical activity at ∼3.8 V vs Na/Na+ with a reversible capacity of 90 mAh g–1 at room temperature. It also shows an excellent cycling and rate performance: 96% capacity retention after 30 cycles and 70% capacity retention at a c-rate increase from 0.05C to 1C. These electrochemical activities of the Mn-containing cathode material even at room temperature with relatively large particle sizes are remarkable considering an almost complete inactivity of the Li counterpart, Li2MnP2O7. Using first-principles calculations, we find that the significantly enhanced kinetics of Na2MnP2O7 is mainly due to the locally flexible accommodation of Jahn–Teller distortions aided by the corner-sharing crystal structure in triclinic Na2MnP2O7. By contrast, in monoclinic Li2MnP2O7, the edge-sharing geometry causes multiple bonds to be broken and formed during charging reaction with a large degree of atomic rearrangements. We expect that the similar computational strategy to analyze the atomic rearrangements can be used to predict the kinetics behavior when exploring new cathode candidates. |
Language | en |
Subject | Batteries Kinetics Materials Redox reactions Transition metals |
Type | Article |
Pagination | 2787-2792 |
Issue Number | 7 |
Volume Number | 135 |
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Chemical Engineering [1155 items ]