On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions

Banerjee, Anjan; Shilina, Yuliya; Ziv, Baruch; Ziegelbauer, Joseph M.; Luski, Shalom; Aurbach, Doron; Halalay, Ion C.

doi:10.1021/jacs.6b10781

Cited by 147 publications

(115 citation statements)

References 31 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…Furthermore, the dissolution of Mn 2+ was accelerated at elevated temperatures due to the decomposition of the electrolyte. The absence of Mn 3+ is contrary to those studies, which reported dissolution of Mn 2+ and Mn 3+ from LMO or LNMO cathode materials into LIB electrolytes [38, 39].…”

Section: Discussioncontrasting

confidence: 84%

“…Nevertheless, several studies report on dissolved Mn 3+ being the main manganese species in common electrolyte in case of the LMO cathode, with abundances of 67–78% after storage and 60–80% after electrochemically treatment in LMO||Graphite cells. For LNMO, the Mn 3+ amount in the electrolyte after storage was reported to be 12–44% of total dissolved manganese [38, 39].…”

Section: Resultsmentioning

confidence: 99%

“…investigated separators from LMO‐based cells after cycling at 50°C, containing polymeric aza‐15‐crown‐5 ethers as Mn ion scavenging agent with XANES, revealing an average oxidation state close to +3 [25]. Other studies showed the dissolution of both manganese species for LNMO and LMO cathode materials in standard carbonate‐based electrolytes after storage and battery operation, with a high fraction of Mn 3+ [38, 39].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

et al. 2020

View full text Add to dashboard Cite

Mn 2+ or Mn 3+ ? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresisA new CE method with ultraviolet-visible detection was developed in this study to investigate manganese dissolution in lithium ion battery electrolytes. The aqueous running buffer based on diphosphate showed excellent stabilization of labile Mn 3+ , even under electrophoretic conditions. The method was optimized regarding the concentration of diphosphate and modifier to obtain suitable signals for quantification. Additionally, the finally obtained method was applied on carbonate-based electrolytes samples. Dissolution experiments of the cathode material LiNi 0.5 Mn 1.5 O 4 (lithium nickel manganese oxide [LNMO]) in aqueous diphosphate buffer at defined pH were performed to investigate the effect of a transition metal-ion-scavenger on the oxidation state of dissolved manganese. Quantification of both Mn species revealed the formation of mainly Mn 3+ , which can be attributed to a comproportionation reaction of dissolved and complexed Mn 2+ with Mn 4+ at the surface of the LNMO structure. It was also shown that the formation of Mn 3+ increased with lower pH. In contrast, dissolution experiments of LNMO in carbonate-based electrolytes containing LIPF 6 showed only dissolution of Mn 2+ .Abbreviations: LIBs, lithium ion batteries; LMO, lithium manganese oxide; LNMO, lithium nickel manganese oxide; SEI, solid electrolyte interphase; TM, transition metal; XANES, Xray absorption near-edge structure spectroscopy Color online: See the article online to view Figs. 1-5 in color.

show abstract

Section: Discussioncontrasting

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

et al. 2020

View full text Add to dashboard Cite

show abstract

“…This behavior is consistent with the involvement of some Mn atoms in a disproportionation reaction, as has been proposed in other Li-ion systems. [47][48][49] However, the total lateral deviation is fairly minimal and the spectra are dominated by the +4 oxidation in all cases. Therefore, the risingedge behavior may be due to subtler effects, including smaller changes in covalency.…”

Section: Resultsmentioning

confidence: 99%

Laboratory-Based X-ray Absorption Spectroscopy on a Working Pouch Cell Battery at Industrially-Relevant Charging Rates

Jahrman

Pellerin

Ditter

et al. 2019

J. Electrochem. Soc.

View full text Add to dashboard Cite

Li-ion battery (LIB) research has continuing importance for the entire range of applications from consumer products to vehicle electrification and grid stabilization. In many cases, standard electrochemical methods only provide an overall voltage or specific capacity, giving an inadequate description of parallel redox processes or chemical gradients at the particle and pack level. X-ray absorption fine structure (XAFS) is frequently used to augment bulk electrochemical data, as it provides element-specific changes in oxidation state and local atomic structure. Such microscopic descriptors are crucial for elucidating charge transfer and structural changes associated with bonding or site mixing, two key factors in evaluating state of charge and modes of cell failure. However, the impact of XAFS on LIB research has been significantly constrained by a logistical barrier: contemporary XAFS work is performed almost exclusively at synchrotron x-ray light sources, where beamtime is infrequent and experiment time-frames are limited. Here we show that modern laboratory based XAFS can not only be applied to, e.g., characterization of ex situ LIB electrode materials, but can also be used for operando studies at industrially-relevant charging rates in a standard pouch cell preparation. Such capability enables accelerated discovery of new materials and improved operation modes for LIBs.(*)

show abstract

“…[12,13,47,[49][50][51][52] During storage in the air, O 2 /H 2 O/CO 2 could also react with these partially coordinated metal cations and so surface reconstruction occurs, leading to species like LiOH, Li 2 CO 3 , and LiHCO 3 at the surface. For example, surface reconstruction occurs commonly in electrodes upon exposure to the electrolyte and/or during electrochemical cycling, as in recent studies, and is attributed to the reaction between organic molecules in the electrolyte and partially coordinated metal cations in MO 6 octahedra at the particle surface.…”

mentioning

confidence: 99%

Cooling Induced Surface Reconstruction during Synthesis of High‐Ni Layered Oxides

Zhang

et al. 2019

Advanced Energy Materials

View full text Add to dashboard Cite

Li-ion batteries (LIBs) are now increasingly used in electric vehicles (EVs) and other large-scale applications, but a bottleneck for their mass adoption is low Li-storage capacity, which is largely constrained by cathodes, typically with a gravimetric capacity equivalent to ≈1/2 that of the graphite anode. Despite much research into candidate cathodes for LIBs, transition metal (TM) layered oxides with a hexagonal structure (space group R3m) have remained dominant over the past three decades. [1,2] In particular, high-Ni layered oxides, LiNi x Mn y Co z O 2 (NMC; x ≥ 0.7) are now attracting world-wide interest for their high theoretical capacity (≈280 mA h g −1 ), which, however, has been difficult to realize due to the issues associated with high Ni loading: [3][4][5][6][7][8] in addition to cationic disordering (Li/Ni mixing) and the resulted low electrochemical activity, [9][10][11] Transition metal layered oxides have been the dominant cathodes in lithiumion batteries, and among them, high-Ni ones (LiNi x Mn y Co z O 2 ; x ≥ 0.7) with greatly boosted capacity and reduced cost are of particular interest for largescale applications. The high Ni loading, on the other hand, raises the critical issues of surface instability and poor rate performance. The rational design of synthesis leading to layered LiNi 0.7 Mn 0.15 Co 0.15 O 2 with greatly enhanced rate capability is demonstrated, by implementing a quenching process alternative to the general slow cooling. In situ synchrotron X-ray diffraction, coupled with surface analysis, is applied to studies of the synthesis process, revealing cooling-induced surface reconstruction involving Li 2 CO 3 accumulation, formation of a Li-deficient layer and Ni reduction at the particle surface. The reconstruction process occurs predominantly at high temperatures (above 350 °C) and is highly cooling-rate dependent, implying that surface reconstruction can be suppressed through synthetic control, i.e., quenching to improve the surface stability and rate performance of the synthesized materials. These findings may provide guidance to rational synthesis of high-Ni cathode materials. (2 of 10)cycling stability and safety are often compromised due to the surface-related issues. [12][13][14][15] Significant efforts in developing high-Ni NMC cathodes have been put on studying electrochemical impact, origin of the Li/ Ni disordering, and on improving Li/Ni ordering through optimizing synthesis conditions. [9,11,16,17] It is until very recently that people started to pay close attention to the surface instability, particularly surface reconstruction, including formation of NiO-type rock salt, [11,18,19] Li 2 CO 3 species, [10,14,[20][21][22] and nickel carbonate (NiCO 3 ·2Ni(OH) 2 ·2H 2 O). [23] These surface species are electrochemically inactive and poor in electronic and ionic conductivity, so causing high impedance to Li + (de)intercalation during cycling, [24,25] and even power fade as reported in LiNi 0.8 Co 0.2 O 2 . [26] The formation of NiO and Li 2 CO 3 at the surface of prima...

show abstract

On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions

Cited by 147 publications

References 31 publications

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

Laboratory-Based X-ray Absorption Spectroscopy on a Working Pouch Cell Battery at Industrially-Relevant Charging Rates

Cooling Induced Surface Reconstruction during Synthesis of High‐Ni Layered Oxides

Contact Info

Product

Resources

About

On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions

Cited by 147 publications

References 31 publications

Mn2+ or Mn3+? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

Mn2+ or Mn3+? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

Laboratory-Based X-ray Absorption Spectroscopy on a Working Pouch Cell Battery at Industrially-Relevant Charging Rates

Cooling Induced Surface Reconstruction during Synthesis of High‐Ni Layered Oxides

Contact Info

Product

Resources

About

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis

Mn²⁺ or Mn³⁺? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis