Sulfated Alginate as an Effective Polymer Binder for High-Voltage LiNi_0.5Mn_1.5O₄ Electrodes in Lithium-Ion Batteries

Abstract

Although the increasing demand for high-energy-density lithium-ion batteries (LIBs) has inspired extensive research on high-voltage cathode materials, such as LiNi0.5Mn1.5O4 (LNMO), their commercialization is hindered by problems associated with the decomposition of common carbonate solvent–based electrolytes at elevated voltages. To address these problems, we prepared high-voltage LNMO composite electrodes using five polymer binders (two sulfated and two nonsulfated alginate binders and a poly(vinylidene fluoride) conventional binder) and compared their electrochemical performances at ∼5 V vs Li/Li+. The effects of binder type on electrode performance were probed by analyzing cycled electrodes using soft/hard X-ray photoelectron spectroscopy and scanning transmission electron microscopy. The best-performing sulfated binder, sulfated alginate, uniformly covers the surface of LNMO and increased its affinity for the electrolyte. The electrolyte decomposition products generated in the initial charge–discharge cycle on the alginate-covered electrode participated in the formation of a protective passivation layer that suppressed further decomposition during subsequent cycles, resulting in enhanced cycling and rate performances. The results of this study provide a basis for the cost-effective and technically undemanding fabrication of high-energy-density LIBs.

High-performance SiO electrodes for lithium-ion batteries: merged effects of a new polyacrylate binder and an electrode-maturation process

“…As seen in the P 1s spectra (Fig. S9 and S12, ESI †), the inorganic species, such as LiPF 6 (2152 eV) and Li x PO y F z (2150 eV) 49,50 were also strongly affected by the charge-up effect, consistent with F 1s spectra.…”

In‐situ Polymerized Single Lithium‐ion Conducting Binder as an Integrated Strategy for High Voltage LNMO Electrodes

“…[40] The constant presence of mobile Li + in SLICPB helps mitigate polarization by concentration, providing an additional advantage; in this regard, it is important to highlight that although the beneficial impact of several binders in protective capability has been reported, no material has been reported to diminish polarization by concentration due to the SLICPBs. [41][42][43][44] At higher C-rates, the disparities between the binders are exacerbated, with a greater difference in capacity between the samples, being higher for AMBB. Furthermore, the slope of the charge curve at high potential remains significantly steeper for AMBB compared to AMFB, and the plateau separation increases as the C-rate rises (Figure 3b-d).…”

“…Secondly, during discharge, there is a slight yet noticeable decrease in the discharge potential towards the end, a behavior traditionally associated with polarization by concentration resulting from a depletion of species near the electrodes, table S2 provide values for discharge potentials using both binders where the advantages of AMBB are evident [40] . The constant presence of mobile Li + in SLICPB helps mitigate polarization by concentration, providing an additional advantage; in this regard, it is important to highlight that although the beneficial impact of several binders in protective capability has been reported, no material has been reported to diminish polarization by concentration due to the SLICPBs [41–44] . At higher C‐rates, the disparities between the binders are exacerbated, with a greater difference in capacity between the samples, being higher for AMBB.…”

Alginate-Xylan Biopolymer as a Multifunctional Binder for 5 V High-Voltage LNMO Electrodes

“…surface coating by AlF 3 and Co 3 O 4 . Additionally, additives might prevent undesirable surface interactions, which would consequently enhance LNMO’s cycle performance. ,− However, both methods involve complex processes at a high cost, depressing their industrial utilization . It is so crucial for developing a straightforward method to increase the high-voltage LNMO’s cycle stability.…”

“…12,27−29 However, both methods involve complex processes at a high cost, depressing their industrial utilization. 30 It is so crucial for developing a straightforward method to increase the high-voltage LNMO's cycle stability.…”