High Cut-off Voltage Research Articles

Synergistically Enhanced Electrochemical Properties of LiNi0.5Co0.2Mn0.3O2 by the Co-Modification of Ti and Na

The layered material of nickel cobalt manganese oxide lithium oxide is one of the most promising lithium-ion battery (LIBs) materials, with the characteristics of high capacity and high density. However, most nickel-rich layered oxides have the phenomenon of cation mixing and the phenomenon that the layered structure changes to the spinel structure during the cycle, which results in poor capacity and cycle performance under high cut-off voltage. Herein, we modified LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 with Ti and Na co-doping to observe the changes in the specific capacity, cycle performance and crystal structure of the material. Ti and Na co-doped LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 has the most obvious effect on increasing the discharge specific capacity and improving the cycle performance. In sthe voltage range of 3–4.5[Formula: see text]V, its discharge specific capacity reaches 183.5[Formula: see text]mAh/gat 0.5C, and the capacity retention rate after 100 cycles is 81.96%, and its discharge specific capacity reaches 164.2[Formula: see text]mAh/g at 1C and after 100 cycles Capacity retention rate is 80.93%. The introduction of Ti and Na plays an important role in improving the cation mixing phenomenon and improving the stability of the crystal structure.

1,2,3,4-Tetrakis(2-cyanoethoxy)butane (TCEB)-Assisted Construction of Self-Repair Electrode Interface Films to Improve the Performance of 4.5 V Pouch LiCoO2/Artificial Graphite Full Cells Operating at 45 °C.

1,2,3,4-Tetrakis(2-cyanoethoxy)butane (TCEB) is first evaluated as a functional electrolyte additive to increase the charge cutoff voltage and energy density of pouch LiCO2 (LCO)/artificial graphite (AG) lithium-ion batteries (LIBs) at a high temperature of 45 °C. The charge (0.7 C) and discharge (1 C) tests show that TCEB effectively improves the cycle stability of cells under a high charge cutoff voltage of 4.5 V. At 25 °C, the capacity retention of the cells with TCEB increases from 0.0% to 72.1% after 1200 cycles. At 45 °C, the capacity retention of the cells without TCEB after 50 cycles is close to 0.0%, while the capacity retention of the cells with TCEB is still 81.6%, even after 350 cycles. The spectroscopic characterization results demonstrate that the TCEB electrolyte additive participates in the construction of a self-repair electrode/electrolyte interface film. Subsequently, low impedance and strong protective layers are formed on the two electrode surfaces. The quantitative analysis results and a theoretical calculation also show that TCEB effectively inhibits the dissolution of Co3+ and maintains the structural integrity of electrode materials. These results indicate that TCEB endows LIBs with excellent cycle stability and is a promising electrolyte additive for the high-voltage and high-temperature conditions of LCO-based LIBs.

Decomposition of Li2O2 as the Cathode Prelithiation Additive for Lithium-Ion Batteries without an Additional Catalyst and the Initial Performance Investigation

Compared to the graphite anode, Si and SiOx-containing anodes usually have a larger initial capacity loss (ICL) due to more parasitic reactions. The higher ICL of the anode can cause significant Li inventory loss in a full cell, leading to a compromised energy density. As one way to mitigate such Li inventory loss, Li2O2 can be used as the cathode prelithiation additive to provide additional lithium. However, an additional catalyst is usually needed to lower its decomposition potential. In this work, we investigate the use of Li2O2 as the cathode prelithiation additive without the addition of a catalyst. Li2O2 decomposition is first demonstrated in coin half-cells with a calculated capacity of 1180 mAh g−1 obtained from Li2O2 decomposition. We then further demonstrate successful Li2O2 decomposition in single-layer pouch (SLP) full cells and evaluate the initial electrochemical performance. Despite its moisture sensitivity, Li2O2 showed reasonable compatibility with dry-room handling. After dry-room handling, Li2O2 decomposition was observed with an onset potential of 4.29 V vs SiOx anode in SLP cells. With Li2O2 addition, the utilization of the Li inventory from cathode active material was improved by 12.9%, and discharge DCR was reduced by 7% while the cells still delivered similar cell capacities. Cycle performance is not evaluated in this paper due to the high cutoff voltage used, but the factors affecting the cycle performance are discussed. Strategies to further improve the practical use of Li2O2 are also discussed.

Shear-resistant interface of layered oxide cathodes for sodium ion batteries

Layered sodium transition metal (TM) oxides exhibit great potential as high energy density cathode materials for sodium-ion batteries (SIBs). The large Na ions, nevertheless, adopts various coordination environments that are dependent of the sodium concentration, giving rise to cyclical gliding of TM layers and P-O phase transitions upon Na extraction/insertion process. The detrimental interlayer-gliding induced phase transformations lead to deteriorated round-trip energy efficiency, rate capability and cycling stability of electrodes. Herein, we demonstrate a shear-resistant interface via the supersaturation of lithium to overcome the interlayer-gliding behavior and inhibit the multiple P-O phase transitions in P2-type Na0.67Mn0.67Ni0.33O2. The results indicate that the nanoscale interface is composed of lithium-enriched O3 nanodomains in the P2 phase matrix, resulting in smooth charge/discharge profiles and superior cycling stability of P2-type Na0.67Mn0.67Ni0.33O2 cathode under a high cut-off voltage of 4.5 V. This work highlights the concept of modulating the interfacial shear stress for improving the long-term cycling stability of high-voltage layered cathode materials that suffer from severe phase transformations.

Enhancing the cycling stability of Ni-rich LiNi0.83Co0.11Mn0.06O2 cathode at 4.5 V via 2,4-difluorobiphenyl additive

Ni-rich LiNixCoyMn1-x-yO2 (Ni-rich NCM; x ≥ 0.8, 0 < y < 1) is the most prominent cathode material to establish a practical high-energy density of lithium-ion batteries for electric vehicle. However, long-term capacity fading limits the commercial applications of Ni-rich NCM, especially at a high cut-off voltage (>4.3 V). Herein, 2,4-difluorobiphenyl (FBP) is proposed as a fluorine-based cathode electrolyte interphase (CEI)-forming additive for Ni-rich LiNi0.83Co0.11Mn0.06O2 (NCM83). The structural characteristics of FBP originate from the overcharge protection of biphenyl, whereas the fluorine atoms are preferable for high-voltage conditions. The addition of 1 wt% FBP to the electrolyte enhances the cycling stability at the 4.5 V cut-off voltage. Electrochemical impedance spectroscopy and rate capability results indicate a fast kinetics at the NCM83 surface with FBP additive upon the formation of a stable CEI. Images from scanning electron microscopy and transmission electron microscopy after 150 cycles of NCM83 show the thin deposit layer of CEI upon introduction of FBP. The X-ray photoelectron spectroscopy results demonstrate the suppression of electrolyte and salt decomposition. This work suggests an opportunity to develop a completely new functional additive by introducing a fluorine component to existing additives.

Steric Effect Tuned Ion Solvation Enabling Stable Cycling of High-Voltage Lithium Metal Battery.

1,2-Dimethoxyethane (DME) is a common electrolyte solvent for lithium metal batteries. Various DME-based electrolyte designs have improved long-term cyclability of high-voltage full cells. However, insufficient Coulombic efficiency at the Li anode and poor high-voltage stability remain a challenge for DME electrolytes. Here, we report a molecular design principle that utilizes a steric hindrance effect to tune the solvation structures of Li+ ions. We hypothesized that by substituting the methoxy groups on DME with larger-sized ethoxy groups, the resulting 1,2-diethoxyethane (DEE) should have a weaker solvation ability and consequently more anion-rich inner solvation shells, both of which enhance interfacial stability at the cathode and anode. Experimental and computational evidence indicates such steric-effect-based design leads to an appreciable improvement in electrochemical stability of lithium bis(fluorosulfonyl)imide (LiFSI)/DEE electrolytes. Under stringent full-cell conditions of 4.8 mAh cm-2 NMC811, 50 μm thin Li, and high cutoff voltage at 4.4 V, 4 M LiFSI/DEE enabled 182 cycles until 80% capacity retention while 4 M LiFSI/DME only achieved 94 cycles. This work points out a promising path toward the molecular design of non-fluorinated ether-based electrolyte solvents for practical high-voltage Li metal batteries.

Stabilizing reaction interface in Ni-rich layered oxides cathode for high-performance lithium-ion batteries at a high cutoff voltage

Nickel-rich layered oxide materials have been considered as promising cathodes for Li-ion batteries (LIBs) due to their high electrochemical capacities and low costs. However, the capacity fading and voltage decay during the cycle at high voltage hinders its practical application, resulting from the surface instability and bulk structural transformation. Here, we constructed a high-voltage-stable interface of Lin(TM)mPO4 (LTMPO, TM = Ni, Co, and Mn) by surface treatment to improve the voltage and capacity stability of LiNi0.8Co0.1Mn0.1O2 (NCM811) during cycling. The formed LTMPO nanolayer with better ionic conductivity and bonds with the surface of host NCM811 by a TM-O-P bond. As a result, the formed LTMPO interface could suppress the occurrence of surface side reactions and oxygen evolution, thus stabilizing the host structure and surface structure. The surface-modified NHP-2 electrode shows excellent capacity retention of 80.36% over 300 cycles at a high cut-off voltage of 4.5 V. This structure design strategy can effectively improve the electrochemical performance of NCM811 cathodes and promote the rapid development of high energy density Li-ion batteries (LIBs).

An Aging Study of NCA/Si-Graphite Lithium-Ion Cells for Off-Grid Photovoltaic Systems in Bolivia

Performance and aging of lithium-ion 18650 cylindrical cells containing NCA and Si-graphite composite electrodes are investigated during long-term low current rate (∼0.1C) cycling protocol resembling charge/discharge profile of off-grid photovoltaic battery system. The cells are cycled within 30% and 75% state-of-charge ranges (∆SOC) with low, middle and high cut-off voltages. Electrochemical impedance spectroscopy data of full cylindrical cells exhibit severe aging for cells that have been cycled at higher cut-off voltage of 4.2 V. Symmetric cell impedance from each electrode shows that aging of NCA is dominant over aging of Si-graphite. Using a Newman-based impedance model, the NCA symmetrical cells’ impedance spectra are parameterized to evaluate the aging modes. The resulting parameterization confirms increased particles’ surface film resistance due to possible electrolyte oxidation and tortuosity increase at high cut-off voltages. Cycling the cells with middle and low cut-off voltages causes few significant changes when compared to calendar-aged samples. This opens up the possibility to significantly increase battery lifetime for small photovoltaic battery systems in rural areas of Bolivia.

Design Parameters for Enhanced Performance of Li1+xNi0.6Co0.2Mn0.2O2 at High Voltage: A Phase Transformation Study by In Situ XRD

The electrochemical performance of Al-doped and un-doped Li1+xNi0.6Co0.2Mn0.2O2 (NCM) cathodes was evaluated at a high cut-off voltage up to 4.6 V (vs Li/Li+) using 1 Ah pouch-type full cells and coin-type half cells. The batteries employing Al-doped NCM exhibited lower internal resistance, higher C-rate capability, and better low-temperature performance. In situ X-ray diffraction revealed that the Al-doped cathode followed a one-phase reaction route, which is attributed to enhanced Li+ diffusion due to Al doping and the relatively small and porous secondary particles. The existence of the pristine phase in undoped NCM throughout the cycling is explained by the slow diffusion of lithium in and out of the large and dense particles, leading to phase separation caused by regions with different lithium concentrations. Analysis using time-of-flight secondary ion mass spectrometry combined with a focused ion-beam scanning electron microscopy confirmed that the Li-ion distribution of undoped NCM was less homogeneous than that of the doped NCM.

PEO based polymer in plastic crystal electrolytes for room temperature high-voltage lithium metal batteries

Lithium metal coupled with high voltage cathodes has been extensively investigated to meet the demand for higher energy density batteries. However, only a few electrolytes are compatible with both lithium anode and high voltage LiNi 0.5 Mn 0.3 Co 0.2 O 2 . Pure poly(ethylene oxide) electrolyte shows high-stability against lithium metal but has limited oxidation stability (typically < 3.8 V). Nitrile-based electrolyte with -C≡N groups exhibits excellent electrochemical stability against high voltage electrodes. Here, a novel type of poly(ethylene oxide) based polymer in plastic crystal (succinonitrile) electrolyte is designed to achieve stable cathode/electrolyte and anode/electrolyte interfaces simultaneously through strong intermolecular interactions. Li-Li symmetric cells with the polymer in plastic crystal electrolyte runs stably for 700 h at 1 mA cm −2 . Even with a high cut-off voltage of 4.4 V, the Li// LiNi 0.5 Mn 0.3 Co 0.2 O 2 cell delivers a high discharge capacity of 169 mA h g −1 and a capacity retention of 80% after 120 cycles. Our work highlights development of PEO-based electrolytes with higher energy density by inter-molecular design. • PIPCE shows a high ionic conductivity, wide electrochemical window and low flammability. • Improved electrochemical stability of PIPCE originates from the inter-molecule interaction. • NMC532/PIPCE/Li delivers a capacity of 169 mA h g -1 with 4.4 V cut-off voltage. • Stable SEI and CEI are formed at the electrolyte/electrode interface.

Understanding the Stabilizing Effects of Nanoscale Metal Oxide and Li-Metal Oxide Coatings on Lithium-Ion Battery Positive Electrode Materials.

Nickel-rich layered oxides, such as LiNi0.6Co0.2Mn0.2O2 (NMC622), are high-capacity electrode materials for lithium-ion batteries. However, this material faces issues, such as poor durability at high cut-off voltages (>4.4 V vs Li/Li+), which mainly originate from an unstable electrode-electrolyte interface. To reduce the side reactions at the interfacial zone and increase the structural stability of the NMC622 materials, nanoscale (<5 nm) coatings of TiOx (TO) and LixTiyOz (LTO) were deposited over NMC622 composite electrodes using atomic layer deposition. It was found that these coatings provided a protective surface and also reinforced the electrode structure. Under high-voltage range (3.0-4.6 V) cycling, the coatings enhance the NMC electrochemical behavior, enabling longer cycle life and higher capacity. Cyclic voltammetry, X-ray photoelectron spectroscopy, and X-ray diffraction analyses of the coated NMC electrodes suggest that the enhanced electrochemical performance originates from reduced side reactions. In situ dilatometry analysis shows reversible volume change for NMC-LTO during the cycling. It revealed that the dilation behavior of the electrode, resulting in crack formation and consequent particle degradation, is significantly suppressed for the coated sample. The ability of the coatings to mitigate the electrode degradation mechanisms, illustrated in this report, provides insight into a method to enhance the performance of Ni-rich positive electrode materials under high-voltage ranges.

A Hybrid Ionic and Electronic Conductive Coating Layer for Enhanced Electrochemical Performance of 4.6 V LiCoO2.

The LiCoO2 cathode undergoes undesirable electrochemical performance when cycled with a high cut-off voltage (≥4.5 V versus Li/Li+). The unstable interface with poor kinetics is one of the main contributors to the performance failure. Hence, a hybrid Li-ion conductor (Li1.5Al0.5Ge1.5P3O12) and electron conductor (Al-doped ZnO) coating layer was built on the LiCoO2 surface. Characterization studies prove that a thick and conductive layer is homogeneously covered on LiCoO2 particles. The coating layer can not only enhance the interfacial ionic and electronic transport kinetics but also act as a protective layer to suppress the side reactions between the cathode and electrolyte. The modified LiCoO2 (HC-LCO) achieves an excellent cycling stability (77.1% capacity retention after 350 cycles at 1C) and rate capability (139.8 mAh g-1 at 10C) at 3.0-4.6 V. Investigations show that the protective layer can inhibit the particle cracks and Co dissolution and stabilize the cathode electrolyte interface (CEI). Furthermore, the irreversible phase transformation is still observed on the HC-LCO surface, indicating the phase transformation of the LiCoO2 surface may not be the main factor for fast performance failure. This work provides new insight of interfacial design for cathodes operating with a high cut-off voltage.

Coating ultra-thin TiN layer onto LiNi0.8Co0.1Mn0.1O2 cathode material by atomic layer deposition for high-performance lithium-ion batteries

Layered structural LiNixCoyMn1−x-yO2 (NCM, Ni ≥ 60%), as a competitive cathode material for high-energy density lithium-ion batteries, has been studied for a long time. However, the structural instability at high cut-off voltage and the erosion of the electrolyte by-product HF during the cycling can result in obvious capacity loss for bare NCM materials, which needs to be overcome for long charge mileage and safety of lithium-ion batteries. In this paper, an ultra-thin TiN film is deposited on the surface of LiNi0.8Co0.1Mn0.1O2 (NCM811) particle by atomic layer deposition (ALD) to improve the electrochemical performance. The TiN coating layer was successfully found to hinder the side reaction and inhibit the damage of the structure during the cycling, reduce the contact resistance between the NCM811 particle and improve the electronic conductivity of the particle surface during the cycling. As a result, the TiN modified NCM811 cathode materials exhibit significantly improved cycling capacities and rate performance. The methodology in this study provides a new path to achieve thin layer surface modification to enhance the performance of electrode materials.

Constructing High Conductive Composite Coating with TiN and Polypyrrole to Improve the Performance of LiNi0.8Co0.1Mn0.1O2 at High Cutoff Voltage of 4.5 V

Constructing High Conductive Composite Coating with TiN and Polypyrrole to Improve the Performance of LiNi_0.8Co_0.1Mn_0.1O₂ at High Cutoff Voltage of 4.5 V

Improved Electrochemical Performance of Al2O3-Coated @ K and Cl Dual-Doped LiNi0.5Co0.2Mn0.3O2 Cathode Materials at High Cut-Off Voltage

Improved Electrochemical Performance of Al2O3-Coated @ K and Cl Dual-Doped LiNi0.5Co0.2Mn0.3O2 Cathode Materials at High Cut-Off Voltage

Cycle parameter dependent degradation analysis in automotive lithium-ion cells

In this study, we report on the operational parameter dependent degradation mechanisms occurring in cycled large-format automotive lithium-ion cells. The comprehension of these mechanisms is a prerequisite for design and operation of long-life lithium-ion cells. The degradation mechanisms are evaluated in dependence of cycle temperature, cut-off voltage, depth of discharge and discharge current, performing an extensive post-mortem analysis on cells subjected to a one-year-long cycle test. The main degradation mechanisms in the cells cycled at 60 °C are the large formation of gas, gas-assisted lithium plating, and, additionally, temperature-accelerated growth of the solid electrolyte interphase (SEI), as revealed by XPS depth-profiling. The growth of the SEI is intensified by using higher cut-off voltages, while transition metal dissolution is observed via STEM. The manganese ions incorporate into the SEI, causing a strong blue coloration of the anodes’ surface. The major effect in the cells cycled at high depth of discharge is the loss of cathode active material, as revealed by ICP-OES, XRD, and FIB-SEM measurements. The variation of the discharge current has no effect on the type of degradation mechanism occurring in the cells cycled at 20% depth of discharge.

A New Fluorinated Sultone as Multifunctional Electrolyte Additive for High‐Performance LiCoO2/Graphite Cell

AbstractThe energy density of lithium cobalt oxide (LiCoO2)‐based cells can be increased by charging at voltages above 4.2 V. However, the poor interface stability of the cathode/electrolyte deriving from the continuous severe decomposition of the electrolyte on the cathode/electrolyte surface and the instability of the structure of the cathode at high‐voltage operation limits their wider commercial application. Herein, a new fluoro‐functionalized electrolyte additive, tetrafluoroethane beta‐sultone (TFBS), is used for promoting the electrochemical performance of LiCoO2‐based cells. Upon cycling between 3.0 and 4.5 V (vs. Li/Li+) with 0.5 C (1 C=274.4 mAh/g), it is shown that the capacity retention of the LiCoO2/graphite pouch‐cell with TFBS‐controlled electrolyte reaches 96.8 % (183.9 mAh g−1), yet it is 66.5 % (126.3 mAh g−1) for the pouch‐cell without TFBS in baseline electrolyte at the 100th cycle. All the results indicate that TFBS can be decomposed prior to the solvents in the electrolyte and can then form low‐resistance, high‐conductivity interface layers on the surfaces of the cathode‐electrolyte and the anode‐electrolyte, respectively, thus improving the cycling stability of the cells at a high charging cutoff voltage (4.5 V).

Tuning oxygen redox chemistry of P2-type manganese-based oxide cathode via dual Cu and Co substitution for sodium-ion batteries

High-voltage layered Mn-based oxide is promising high-capacity cathode via exploiting the oxygen redox chemistry. But such redox often suffer from irreversible oxygen loss, leading to severe voltage hysteresis, particle cracking and capacity decay. Hence, the complementary strategy of dual Cu and Co substitution is revealed to stabilizing the anion redox chemistry of P2-Na2/3(Mn-Ni-Cu-Co)O2 cathode under upper cut-off voltage. Dual substitution with Cu for Mn and Co for Ni forms stable Cu-O and Co-O octahedrons, which modulate the lattice structure with the shrinkage of TMO2 sheets and expansion of Na layer spacing to enhance the Na+ diffusion kinetics. Co substitution can raise high voltage region to tune the cut-off voltage up to 4.3 V and activate oxygen redox to weaken irreversible O2 loss. And Cu substitution can inhibit the O2 loss and suppress the voltage decay via the interaction between Cu 3d and O 2p orbitals. The P2-type Na0.67Mn0.6Ni0.2Cu0.1Co0.1O2 cathode induced by the complementary effect can boost long cycling life (82.07% capacity retention after 500 cycles) and remarkable rate capability under high upper cut-off voltage in half-cell. Furthermore, the full cells also exhibit outstanding rate capability with a high discharge capacity of 62.6 mAh g–1 at 20 C.

LiF and LiNO3 as synergistic additives for PEO-PVDF/LLZTO-based composite electrolyte towards high-voltage lithium batteries with dual-interfaces stability

Solid electrolytes with desirable properties such as high ionic conductivity, wide electrochemical stable window, and suitable mechanical strength, and stable electrode–electrolyte interfaces on both cathode and anode side are essential for high-voltage all-solid-state lithium batteries (ASSLBs) to achieve excellent cycle stability. In this work, a novel strategy of using LiF and LiNO3 as synergistic additives to boost the performance of PEO-PVDF/LLZTO-based composite solid electrolytes (CSEs) is developed, which also promotes the assembled high-voltage ASSLBs with dual-interfaces stability characteristic. Specifically, LiF as an inactive additive can increase the electrochemical stability of the CSE under high cut-off voltage, and improve the high-voltage compatibility between cathode and CSE, thus leading to a stable cathode/CSE interface. LiNO3 as an active additive can lead to an enhanced ionic conductivity of CSE due to the increased free-mobile Li+ and ensure a stable CSE/Li interface by forming stable solid electrolyte interphase (SEI) on Li anode surface. Benefiting from the improved performance of CSE and stable dual-interfaces, the assembled NCM622/9[PEO15-LiTFSI]-PVDF-15LLZTO-2LiF-3LiNO3/Li cell delivers a high rate capacity of 102.1 mAh g−1 at 1.0 C and a high capacity retention of 77.4% after 200 cycles at 0.5 C, which are much higher than those of the ASSLB assembled with additive-free CSE, with only 60.0 mAh g−1 and 52.0%, respectively. Furthermore, novel cycle test modes of resting for 5 h at different charge states after every 5 cycles are designed to investigate the high-voltage compatibility between cathode and CSE, and the results suggest that LiF additive can actually improve the high-voltage compatibility of cathode and CSE. All the obtained results confirm that the strategy of using synergistic additives in CSE is an effective way to achieve high-voltage ASSLBs with dual-interfaces stability.

Improving the electrochemical performance of LiNi0.6Co0.1Mn0.3O2 cathode at high cutoff voltage by dual functions of Y(PO3)3 modification

Layered nickel-rich ternary materials LiNixCoyMn1-x-yO2 have been deemed as the most practical candidates in the power battery industry on account of their high capacity and low cost. In the study, we investigated the modifying impacts of Y(PO3)3 on structure and electrochemical properties of LiNi0.6Co0.1Mn0.3O2 (NCM613) material. The characterization results show that trace amounts of yttrium may be incorporated into the crystals of NCM613 material, and the remaining Y(PO3)3 reacted with the surface residual lithium to produce a hybrid YPO4-Li3PO4-Y(PO3)3 coating layer on the surface of NCM613 grains. The modified-NCM613 with 0.3 wt% Y(PO3)3 presents high initial discharge specific capacities of 181.3 mAh g−1 and 196.0 mAh g−1 in 2.8–4.5 V (vs Li/Li+) at 1C under 25 °C and 45 °C, and maintains 87.2% and 82.1% retentions after 100 cycles, higher than those of the unmodified NCM613 (71.8% and 65.8%). The improved electrochemical performance of 0.3 wt% Y(PO3)3 modified-NCM613 results from dual functions of Y3+ doping and the hybrid YPO4-Li3PO4-Y(PO3)3 coating. The Y3+ doping can improve lithium ion diffusion rate and promote the layered structural stability. The hybrid coating suppresses the corrosion of electrolyte to the cathode material in cycles.