Revealing the mitigation of intrinsic structure transformation and oxygen evolution in a layered Li1.2Ni0.2Mn0.6O2 cathode using restricted charging protocols

Lin, Ming‐Hsien; Cheng, Ju‐Hsiang; Huang, Hsin‐Fu; Chen, U-Fo; Huang, Chun-Ming; Hsieh, He-Yen; Lee, J. M.; Chen, Jin‐Ming; Su, Wei‐Nien; Hwang, Bing‐Joe

doi:10.1016/j.jpowsour.2017.05.089

Cited by 39 publications

(29 citation statements)

References 56 publications

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“…the capacity ratio of the anode to cathode (A/C) is > 1 and cathode is the limiting electrode, the excess metallic Li will compensate the active Li loss due to dead Li formation and reductive electrolyte decomposition at the anode side, leading them invisible from the irr-CE observed. Since the irreversible reactions at the anode cannot be observed, this protocol acts as an efficient tool to extract information relating to the irreversible reactions at the cathode including oxidative electrolyte decomposition, cathode degradation, and 1 st intrinsic irreversible capacity of cathode material in the 1 st cycle 33,34,35,36,37 . Generally, the irr-CE of cathode//Li cells in the 1 st cycle is often found larger due to the cathode-electrolyte interphase (CEI) formation and additional side reactions than that in the subsequent cycles.…”

Section: Resultsmentioning

confidence: 99%

Unfolding the Hidden Message of Anode-Free Lithium Metal Battery

Huang¹,

Thirumalraj²,

Tao³

et al. 2020

Preprint

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Lithium metal batteries (LMBs) have been revisited and gained great attention due to significantly mitigated formation of Li dendrite in the past decade. Recently, anode-free lithium metal batteries (AFLMBs) are proposed and have been studied intensively to potentially outperform LMBs due to higher energy density and reduced safety hazards since the absence of Li metal during the fabrication process of the cell. In general, researchers compare capacity retention, reversible capacity, or rate capability of the cells to study the electrochemical performance of batteries. However, evaluating the behavior of batteries from limited aspects would easily overlook other information hidden deep inside the meretricious results or even lead to misguided data interpretation. In this work, an integrated protocol combining different types of cell configuration is proposed and validated for the first time to unravel the concealed messages in LMBs and AFLMBs. Irreversible coulombic efficiency (irr-CE) from various contributions including reductive electrolyte decomposition, dead Li formation, 1st intrinsic irreversible capacity of a cathode, and the subsequent irreversible reactions at cathode containing oxidative electrolyte decomposition and cathode degradation upon cycling are successfully determined separately by the integrated protocol for the first time. The decrypted information obtained from the proposed protocol provides an insightful understanding of behaviors of LMBs and AFLMBs, which promotes their development for practical applications.

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Section: Resultsmentioning

confidence: 99%

Unfolding the Hidden Message of Anode-Free Lithium Metal Battery

Huang¹,

Thirumalraj²,

Tao³

et al. 2020

Preprint

Self Cite

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“…Figure 5a, b present the Mn L-edge sXAS spectra of the LNCMO-s and LNCMO-p series collected under TEY mode, respectively. After 1 and 50 cycles (Figure 5a, b), two [44] we conclude that the valence states of Mn ions are changed to + 2 and + 3 in the discharged state, which indicates a more contribution of Mn in charge compensation during the lithium insertion process of LNCMO-s. Clearly, the Mn L II,III -edge spectral shapes obtained for the two pristine samples both correspond to + 4 ground state, with a main Mn L III -edge peak at 644 eV and a sub-peak at 641.5 eV.…”

Section: Soft Xas Analysismentioning

confidence: 85%

“…Clearly, the Mn L II,III -edge spectral shapes obtained for the two pristine samples both correspond to + 4 ground state, with a main Mn L III -edge peak at 644 eV and a sub-peak at 641.5 eV. After 1 and 50 cycles (Figure 5a, b), two [44] we conclude that the valence states of Mn ions are changed to + 2 and + 3 in the discharged state, which indicates a more contribution of Mn in charge compensation during the lithium insertion process of LNCMO-s. This leads to the progressive change from original layered structure to spinel-like phase on the surface of LNCMO-s electrode.…”

Section: Soft Xas Analysismentioning

confidence: 90%

“…The spectrum of Li 2 MnO 3 is also presented as reference for the + 4 oxidation state. [44] Another possibility is the Jahn-Teller effect of active Mn 3 + and the irreversible migration of manganese ions, resulting in the structural instability and the voltage fade. After 1 and 50 cycles (Figure 5a, b), two [44] we conclude that the valence states of Mn ions are changed to + 2 and + 3 in the discharged state, which indicates a more contribution of Mn in charge compensation during the lithium insertion process of LNCMO-s.…”

Section: Soft Xas Analysismentioning

confidence: 99%

“…This leads to the progressive change from original layered structure to spinel-like phase on the surface of LNCMO-s electrode. [44] Another possibility is the Jahn-Teller effect of active Mn 3 + and the irreversible migration of manganese ions, resulting in the structural instability and the voltage fade. [45,46] With regard to the case of LNCMO-p (Figure 5b), the difference in the Mn L-edge spectra at the pristine and discharged state after the 100th cycle is much smaller than that of the LNCMO-s sample (Figure 5a), showing better reversibility of the structure.…”

Section: Soft Xas Analysismentioning

confidence: 99%

See 2 more Smart Citations

Retarding Phase Transformation During Cycling in a Lithium‐ and Manganese‐Rich Cathode Material by Optimizing Synthesis Conditions

Lou

et al. 2019

ChemElectroChem

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Li-rich layered oxides with superior energy density have become appealing alternative cathode materials for nextgeneration lithium-ion batteries. However, they still suffer from voltage decay and irreversible capacity loss due to an undesirable phase transition. Normally, the phase transition is caused by the reduction of Mn ions and migration of the transition metals. In order to address this issue, we herein report a facile and efficient strategy to fabricate a well-structured Li-rich layered Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 by an optimized sol-gel method. Experimentally we find that the as-synthesized layered oxide delivers a high initial discharge capacity as high as 279 mAh g À 1 at 0.1 C and remains a capacity of 250 mA g À 1 after 100 cycles when used as a cathode for lithium-ion batteries. Mn L-edge and O K-edge soft X-ray absorption spectra reveal that the reduction of Mn ions and the migration of transition metals have been well mitigated.

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Restraining Oxygen Release and Suppressing Structure Distortion in Single‐Crystal Li‐Rich Layered Cathode Materials

Sun

Sheng

Cao

et al. 2021

Adv Funct Materials

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Li‐rich oxides can be regarded as the next‐generation cathode materials for high‐energy‐density Li‐ion batteries since additional oxygen redox activities greatly increase output energy density. However, the oxygen loss and structural distortion induce low initial coulombic efficiency and severe decay of cycle performance, further hindering their industrial applications. Herein, the representative layered Li‐rich cathode material, Li1.2Ni0.2Mn0.6O2, is endowed with novel single‐crystal morphology. In comparison to its polycrystal counterpart, not only can serious oxygen release be effectively restrained during the first oxygen activation process, but also the layered/spinel phase transition can be well suppressed upon cycling. Moreover, the single‐crystal cathode exhibits the limited volume change and persistent presence of superlattice peaks upon Li+ (de)intercalation processes, resulting in enhanced structural stability with absence of crack generation and successive utilization of oxygen redox reaction during long‐term cycling. Benefiting from these unique features, the single‐crystal Li‐rich electrode not only yields a high reversible capacity of 257 mAh g−1, but also achieves excellent cycling performance with 92% capacity retention after 200 cycles. These findings demonstrate that the morphology design of single crystals can be regarded as an effective strategy to realize high‐energy density and long‐life Li‐ion batteries.

show abstract

Revealing the mitigation of intrinsic structure transformation and oxygen evolution in a layered Li1.2Ni0.2Mn0.6O2 cathode using restricted charging protocols

Cited by 39 publications

References 56 publications

Unfolding the Hidden Message of Anode-Free Lithium Metal Battery

Unfolding the Hidden Message of Anode-Free Lithium Metal Battery

Retarding Phase Transformation During Cycling in a Lithium‐ and Manganese‐Rich Cathode Material by Optimizing Synthesis Conditions

Restraining Oxygen Release and Suppressing Structure Distortion in Single‐Crystal Li‐Rich Layered Cathode Materials

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