Strategies to Avert Electrochemical Shock and Their Demonstration in Spinels
We demonstrate that extensive electrochemical shock–electrochemical cycling induced fracture–occurs due to coherency stresses arising from first order cubic-to-cubic phase transformations in the spinels LiMn[subscript 2]O[subscript 4] and LiMn[subscript 1.5]Ni[subscript 0.5]O[subscript 4]. Electroch...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Electrochemical Society
2016
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| Online Access: | http://hdl.handle.net/1721.1/101765 https://orcid.org/0000-0001-7564-7173 https://orcid.org/0000-0002-0833-7674 |
| Summary: | We demonstrate that extensive electrochemical shock–electrochemical cycling induced fracture–occurs due to coherency stresses arising from first order cubic-to-cubic phase transformations in the spinels LiMn[subscript 2]O[subscript 4] and LiMn[subscript 1.5]Ni[subscript 0.5]O[subscript 4]. Electrochemical shock occurs despite the isotropy of the shape changes in these materials. This electrochemical shock mechanism is strongly sensitive to particle size; for LiMn[subscript 2]O[subscript 4] and LiMn[subscript 1.5]Ni[subscript 0.5]O[subscript 4], fracture can be averted with particle sizes smaller than ~1 μm. As a further critical test of the proposed mechanism, iron-doping was used to induce continuous solid solubility of lithium in LiMn[subscript 1.5]Ni[subscript 0.5]O[subscript 4], and shown to virtually avert electrochemical shock, while having minimal impact on the electrode potential and capacity. |
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