Developing a Double Protection Strategy for High-Performance Spinel LiNi_0.5Mn_1.5O₄ Cathodes

Abstract

LiNi0.5Mn1.5O4 is a promising cathode material with high-voltage and three-dimensional lithium-ion transport channels. Rapid capacity degradation due to HF corrosion has been a great challenge hindering the application of high-voltage cathode materials. Herein, a double protection strategy for high-performance LiNi0.5Mn1.5O4 cathodes has been designed using Li6.4La3Zr1.4Ta0.6O12 (LLZTO) with both high ionic conductivity and high surface basicity as the modifier of the poly­(vinylidene fluoride) (PVDF) binder and the HF scavenger. It has been demonstrated that the modified PVDF binder possesses a higher Li+ diffusion coefficient than incipient PVDF, resulting in better overall electrochemical properties. Meanwhile, the result of first-principles calculations revealed that the reaction between HF and LLZTO has higher chemical reactivity than that between HF and LiNi0.5Mn1.5O4. The scanning electron microscopy images further confirmed that the insoluble byproducts produced by HF corrosion deposit on the surface of LLZTO particles only because of the high chemical reactivity between HF and LLZTO, while the LNMO particles are well preserved. The modified LNMO-LLZTO cathode presents better cycling stability (even at elevated temperature) and rate capability than the LNMO cathode. This work provides a novel design strategy for high-performance lithium-ion batteries.

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

“…Other approaches have reported capacity decay of around 13 % after 300 cycles in comparison we obtain 6 % decay at the same number of cycles and 7-6 % for 500 cycles (Figure 4b). [41,44,46] Likewise, dQ/dV plots (Figure 4c) confirm a clear pattern of voltage plateau degradation becomes evident after 500 cycles. AMFB exhibits slightly higher reactivity during oxidation at high potentials compared to AMBB and that the plateau-like behavior is lost during cycling.…”

“…[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).…”

Advanced Electrode Materials in Capacitive Deionization for Lithium Recovery

“…During the development of LiMn2O4 (LMO) electrodes, researchers found that the drawback lies in the inevitable dissolution of Mn during the cycle of lithium-ion adsorption and desorption, which can lead to serious problems such as capacity decay and poor cycling performance, among others [3,18]. To address this issue, LMO electrodes are being improved to reduce Mn dissolution, and manganese spinel can be doped with other metal cations to lower the Mn 3+ content in LMO, which will reduce Mn 2+ dissolution and enhance electrochemical performance.…”

“…To address this issue, LMO electrodes are being improved to reduce Mn dissolution, and manganese spinel can be doped with other metal cations to lower the Mn 3+ content in LMO, which will reduce Mn 2+ dissolution and enhance electrochemical performance. Among these, the addition of Ni to LMO to create LiNi0.5Mn1.5O4 (LNMO) has demonstrated outstanding system cycling stability and a high potential to attract the interest of several researchers [1,18,19].…”

Dual Energy Storages by Sequential “Rocking Chair” and “Dual Ion” Processes of LiFe0.6Mn0.4PO4/Carbon Modified Graphite Flakes

“…Developing high voltage cathode materials is an efficient way to meet demands for high-energy-density lithium-ion batteries (LIBs), in addition to high-capacity cathode materials, − such as LiNi 0.5 Mn 1.5 O 4 (4.7 V vs Li/Li + ) and LiCoPO 4 (4.8 V vs Li/Li + ). However, the limited lithium and cobalt resources may hinder their wide application. , Different from the “rocking chair” energy storage of LIBs, dual ion batteries (DIBs) store energy by anion (PF 6 – , TFSI – , AlCl 4 – , etc.)…”