Lithium-ion Battery Cathode Research Articles

Ferrocene-Based Polymer Organic Cathode for Extreme Fast Charging Lithium-Ion Batteries with Ultralong Lifespans.

To meet the growing demand for energy storage, lithium-ion batteries (LIBs) with fast charging capabilities has emerged as a critical technology. The electrode materials affect the rate performance significantly. Organic electrodes with structural flexibility support fast lithium-ion transport and are considered promising candidates for fast-charging LIBs. However, it is a challenge to create organic electrodes that can cycle steadily and reach high energy density in a few minutes. To solve this issue, accelerating the transport of electrons and lithium ions in the electrode is the key. Here, it is demonstrated that a ferrocene-based polymer electrode (Fc-SO3Li) can be used as a fast-charging organic electrode for LIBs. Thanks to its molecular architecture, LIBs with Fc-SO3Li show exceptional cycling stability (99.99% capacity retention after 10 000 cycles) and reach an energy density of 183Wh kg-1 in 72 seconds. Moreover, the composite material through insitu polymerization with Fc-SO3Li and 50 wt % carbon nanotube (denoted as Fc-SO3Li-CNT50) achieved optimized electron and ion transport pathways. After 10000 cycles at a high current density of 50C, it delivered a high energy density of 304Wh kg-1. This study provides valuable insights into designing cathode materials for LIBs that combine high power and ultralong cycle life.

Utilizing Electronic Resistance Measurement for Tailoring Lithium-Ion Battery Cathode Formulations

Cathode formulation, which describes the amount of cathode active material (CAM), conductive additives (CAs), and binder within a cathode compound, is decisive for the performance metrics of lithium-ion battery (LIB) cells. The direct measurement of electronic resistance can be an enabler for more time- and cost-efficient cathode formulation improvements. Within this work, we correlate the electronic resistance with the electrochemical performance of cathodes. Two different high Nickel NCM cathode materials and numerous CAs are used to validate the findings. A detailed look into the resistance reduction potential of carbon black (CB) and single-walled carbon nanotubes (SWCNT) and their mixtures is made. Finally, an impact estimation of cathode formulation changes on LIB key performance factors, such as energy density and cost, is shown.

Controlling lithium cobalt oxide phase transition using molten fluoride salt for improved lithium-ion batteries

LiCoO2 is a historic lithium-ion battery cathode that continues to be used today because of its high energy density. However, the practical capacity of LiCoO2 is limited owing to the harmful phase transition at high voltages, which prevents the realization of its theoretical capacity. Here, we treat LiCoO2 particles with a molten salt of MgF2–LiF as a reaction accelerator to facilitate the diffusion and doping of magnesium into bulk LiCoO2 and to form a stable coating layer on the particle surface. Ex situ X-ray diffraction analysis confirms the inhibition of the harmful phase transition and the emergence of a different phase as the modified LiCoO2 was charged up to 4.7 V. The modified LiCoO2 shows high electrochemical performance during high-voltage operation. This technology provides a guideline for the suppressing fundamental degradation associated with phase transition and achieving ultra-high energy density LiCoO2 cathodes.

Tailoring cathode materials: A comprehensive study on LNMO/LFP blending for next generation lithium-ion batteries

Lithium-ion batteries (LIBs) play a crucial role in diverse applications, including electric vehicles, portable electronics, and grid energy storage, owing to their commendable features, such as high energy density, extended cycle life, and low self-discharge rates. Despite their widespread use, the growing market demands continuous efforts to enhance LIBs performance, particularly in terms of energy density and cycling stability. This paper details the development of a lithium nickel manganese oxide (LNMO - LiNi0·5Mn1·5O4)/lithium iron phosphate (LFP - LiFePO4) blended cathode for high-performance LIBs. The study investigates the impact of blending LFP and LNMO, examining morphological and electrochemical aspects. The usage of resonant acoustic mixing (RAM) technology is demonstrated to be a promising approach to improve the distribution of LFP and LNMO particles, leading to increased electrochemical performance. The blended LNMO/LFP cathode exhibits a specific capacity exceeding 125 mAh g−1 at C/10 and a capacity retention exceeding 80 % after 1000 cycles at 1C versus lithium. Moreover, in a full-cell configuration, the blended electrode displays a capacity retention close to 74 % after 100 cycles, showcasing a nearly 30 % improvement compared to the pure LNMO cathode. This research highlights the potential of blended cathode materials in advancing the capabilities of LIBs.

Constructing High-Performance Cobalt-Based Environmental Catalysts from Spent Lithium-Ion Batteries: Unveiling Overlooked Roles of Copper and Aluminum from Current Collectors.

Converting spent lithium-ion batteries (LIBs) cathode materials into environmental catalysts has drawn more and more attention. Herein, we fabricated a Co3O4-based catalyst from spent LiCoO2 LIBs (Co3O4-LIBs) and found that the role of Al and Cu from current collectors on its performance is nonnegligible. The density functional theory calculations confirmed that the doping of Al and/or Cu upshifts the d-band center of Co. A Fenton-like reaction based on peroxymonosulfate (PMS) activation was adopted to evaluate its activity. Interestingly, Al doping strengthened chemisorption for PMS (from -2.615 eV to -2.623 eV) and shortened Co-O bond length (from 2.540 Å to 2.344 Å) between them, whereas Cu doping reduced interfacial charge-transfer resistance (from 28.347 kΩ to 6.689 kΩ) excepting for the enhancement of the above characteristics. As expected, the degradation activity toward bisphenol A of Co3O4-LIBs (0.523 min-1) was superior to that of Co3O4 prepared from commercial CoC2O4 (0.287 min-1). Simultaneously, the reasons for improved activity were further verified by comparing activity with catalysts doped Al and/or Cu into Co3O4. This work reveals the role of elements from current collectors on the performance of functional materials from spent LIBs, which is beneficial to the sustainable utilization of spent LIBs.

Exploring Phenolphthalein Polyarylethers as High-Performance Alternative Binders for High-Voltage Cathodes in Lithium-Ion Batteries.

Polyvinylidene fluoride (PVDF) has unique electrochemical oxidation resistance and is the only binder for high-voltage cathode materials in the battery industry for a long time. However, PVDF still has some drawbacks, such as environmental limitations on fluorine, strict requirements for environmental humidity, weak adhesion, and poor lithium ion conductivity. Herein, the long-standing issues associated with high-voltage lithium cobalt oxide (LiCoO2; LCO) are successfully addressed by incorporating phenolphthalein polyetherketone (PEK-C) and phenolphthalein polyethersulfone (PES-C) as binder materials. These binders have unexpected electrochemical oxidation resistance and robustness adhesion, ensure uniform coverage on the surface of LCO, and establish an effective and fast ion-conductive CEI/binder composite layer. By leveraging these favorable characteristics, electrodes based on polyarylether binders demonstrate significantly better cycling and rate performance than their counterparts using traditional PVDF binders. The fast ion-conductive CEI/binder composite layer effectively mitigates adverse reactions at the cathode-electrolyte interface. As anticipated, batteries utilizing phenolphthalein polyarylether binders exhibit capacity retention rates of 88.92% and 80.4% after 200 and 500 cycles at 4.5 and 4.6V, respectively. The application of binders, such as polyarylether binders, offers a straightforward and inspiring approach for designing high-energy-density battery materials.

Practical surface-reconstruction strategy based on self-reactive interface design enables ultralong cyclability of commercial cathodes for lithium-ion batteries

Although Al-doped high-voltage LiCoO2 (HVLCO) cathode has been widely used in commercial lithium-ion batteries, it still suffers from poor cycling stability due to its unstable surface/interface structure causing bad side reactions. Herein, a surface reconstruction strategy based on self-reactive interface design has been proposed, to construct a uniform and ultrathin (∼ 5 nm) LiAlO2 (LAO) layer on the surface of HVLCO cathodes. The construction of LAO layer is realized by a facile and scalable process involving chemical immersion in LiOH solution and subsequent heating treatment. Moreover, the LAO coating layer imparts both lower interior stress upon lithiation and lower migration energy barrier of Li ions, guaranteeing stable and rapid lithium storage, which is confirmed by substantial characterizations and theory calculations. Consequently, ultralong cycle life over 10,000 h (1000 cycles) at 0.1 C is achieved for the surface-reconstructed HVLCO cathode, with an 86% capacity retention. Especially, different kinds of commercial HVLCO products as well as NCM (LiNi0.6Co0.2Mn0.2O2) cathode material, after the same surface reconstruction, also show remarkably reinforced electrochemical performance. This practical surface-reconstruction strategy may serve as a useful guideline for future design and performance optimization of commercial cathode materials.

Continuous multicolumn ion exchange process for spent lithium-ion battery leachate: Recovery and purification of a Li+Ni+Co mixture

A continuously operated ion exchange process scheme for the recovery and purification of valuable metals from acid leachates of spent Lithium-ion battery cathodes was developed. The aim is to provide a versatile and industrially feasible alternative for liquid–liquid extraction and precipitation for recycling of spent Li-ion batteries. A chelating resin with aminomethylphosphonic acid functional group (Lewatit® MDS TP 260) was used in a laboratory-scale multicolumn configuration that combined counter-current and cross-current operations. The process was operated at 60 °C with a synthetic leachate with pH 1.8 as the feed. A two-step desorption procedure (1.0 M sulfuric acid (H2SO4) followed by 0.4 M potassium oxalate (K2C2O4)) was found to prevent accumulation of strongly bound metals in the resin. 1 M H2SO4 was found sufficient for regeneration. Pure raffinate containing Li, Ni, and Co was successfully separated from impurity metals (Mn, Cu, Al, and Fe). In steady state operation, no loss of ion exchange capacity was observed. The process was optimized experimentally with focus on the effect of fresh feed and eluent flow rates to increase the productivity and improve the recovery rates of the target metals while maintaining a raffinate purity of 100 %. Increasing the amount of leachate processed per switch was found to enhance the recovery of Co, Li and Ni due to the displacement effect. Very high recovery yields (96.97 % for Co, 99.15 % for Ni, and 100 % for Li) were achieved. The laboratory scale unit could process 1.64L(L·h)−1 of leachate to yield 34.04 g(L·h)−1 of Li+Ni+Co mixture in the raffinate. Moreover, Cu+Mn and Al+Fe rich extract streams with 84.74 % and 97.46 % purities were obtained as by-products. With respect to the recovery rates, the continuous ion exchange process is superior to batchwise operation of ion exchange columns, conventional solvent extraction and not to mention precipitation processes making it a viable alternative in hydrometallurgical LIB recycling.

Multiple-functional LiTi2(PO4)3 modification improving long-term performances of Li-rich Mn-based cathode material for advanced lithium-ion batteries

Li-rich layered oxides with high energy densities have become one kind of promising cathode for advanced lithium-ion batteries, however some issues are severely hindering their practical applications. To address these challenges, fast ion conductive LiTi2(PO4)3 (LTPO) is employed to modify the typical Li-rich cathode Li1·2Mn0·56Ni0·17Co0·07O2 (LMNCO) via a sol-gel process combined with a two-step annealing treatment in this work. Serving as a physical separator, LTPO coating effectively depresses the side reactions at cathode-electrolyte interface and the transition-metal dissolution from LMNCO active material under harsh electrochemical environment. Meanwhile, LTPO layer with high ion conductivity could facilitate the interfacial Li+ diffusion during charge/discharge process. In addition, partial Ti4+ ions doped into LMNCO effectively elevate the oxygen electronegativity and restrain the excessive oxidization of lattice oxygen, thus stabilizing the crystal structure and alleviating the stress-strain propagation upon cycling. Electrochemical characterization results demonstrate that the LTPO-modified LMNCO cathode exhibits a superior capacity retention of 86.5 % after 400 cycles at room temperature and that of 73.7 % even under an elevated temperature of 45 °C after 250 cycles under 1C. This study provides a facile strategy for the surface modification of Li-rich layered-structure oxides, which also sheds light in enhancing electrochemical performances for various cathode materials.

The development of China’s monopoly over cobalt battery materials

While previous resource conflicts have often been linked to fuel minerals such as oil, future resource conflict may revolve around nonfuel minerals that enable strategic emerging technologies. During a 2010 diplomatic dispute, China reportedly blocked exports of rare earth elements to Japan, thereby leveraging China’s near-monopoly to threaten Japanese manufacturers of advanced technologies including batteries and permanent magnets. Although this caused significant concern for manufacturers outside China, China’s control over other critical minerals has yet to be studied comprehensively. Besides rare earth elements, perhaps no mineral has received more attention for its supply risks than cobalt. Here Chinese control is estimated for each cobalt material at each stage of the cobalt supply chain from 2000 through 2022. The results show that from mining, to refining, consumption, recycling, stocks, and trade, China dominates the cobalt materials that feed lithium-ion battery cathode production. Specifically, the results show that in 2022 Chinese firms had control over 62% of cobalt mine materials primarily used for cobalt chemical refining, 95% control of refined commercial-grade cobalt chemicals, 92% control of battery-grade tricobalt tetroxide, 85% control of battery-grade cobalt sulfate, and 91% control of nickel–cobalt-manganese cathode precursor materials. China’s monopoly over cobalt battery materials may imply a serious supply risk to non-Chinese battery producing and consuming industries—especially given rising geopolitical tensions and the reemergence of critical mineral export restrictions including gallium for semiconductors, germanium for solar panels, graphite for lithium-ion batteries, and (again) rare earth elements.

Electrolyte-Enabled High-Voltage Operation of a Low-Nickel, Low-Cobalt Layered Oxide Cathode for High Energy Density Lithium-Ion Batteries.

The lithium-ion battery industry acknowledges the need to reduce expensive metals, such as cobalt and nickel, due to supply chain challenges. However, doing so can drastically reduce the overall battery energy density, attenuating the driving range for electric vehicles. Cycling to higher voltages can increase the capacity and energy density but will consequently exacerbate cell degradation due to the instability at high voltages. Herein, an advanced localized high-concentration electrolyte (LHCE) is utilized to enable long-term cycling of a low-Ni, low-Co layered oxide cathode LiNi0.60Mn0.31Co0.07Al0.02O2 (NMCA) in full cells with graphite or graphite-silicon anodes at 4.5V (≈4.6 vs Li+/Li). NMCA cells with the LHCE deliver a high initial capacity of 194mAhg-1 at C/10 rate along with 73% capacity retention after 400 cycles compared to 49% retention in a baseline carbonate electrolyte. This is facilitated by reduced impedance growth, active material loss, and gas evolution with the NMCA cathode. These improvements are attributed to the formation of robust, inorganic-rich interphase layers on both the cathode and anode throughout cycling, which are induced by a favorable salt decomposition in the LHCE. This study demonstrates the efficacy of electrolytes toward facilitating the operation of high-energy-density, long-life, and cost-effective cathodes.

Approaching Ultimate Synthesis Reaction Rate of Ni-Rich Layered Cathodes for Lithium-Ion Batteries

HighlightsA series of layered oxide cathode materials were synthesized by high-temperature shock strategy for the first time.The approaching ultimate solid reaction rate of the layered nickel-rich layered oxide LiNixCoyMnzO2 was investigated for the first time. Ultrafast average reaction rate of phase transition from Ni0.6Co0.2Mn0.2(OH)2 to Li-containing oxides is 66.7 (% s-1), that is, taking only 1.5 s.

Tổng hợp vật liệu LiNi0,9Mn0,05Co0,05O2 bằng phương pháp phản ứng pha rắn (NMC9.5.5-PR) ứng dụng chế tạo pin ion liti

Nickel-manganese-cobalt (NMC) transition metal oxide-based layered structural materials are evaluated a promising material for applications as cathode in lithium-ion batteries. In this study, we have successfully synthesized nickel-rich NMC material LiNi0.9Mn0.05Co0.05O2 by solid-state reaction method (NMC9.5.5- PR). The CR2032-type lithium-ion battery is also successfully fabricated from NMC material to serve the study of electrochemical properties. The NMC9.5.5-PR material exhibits outstanding discharge specific capacity when providing a maximum specific capacity of up to 212.4 mAh/g at a current density of 10 mA/g. However, the cycle efficiency survey results show that the NMC9.5.5-PR material has some disadvantages (only maintaining 81.6% of the discharge specific capacity after 50 continuous charge-discharge cycles at current density of 10 mA/g). These electrochemical properties indicate that it is necessary to further improve the cyclic efficiency of NMC9.5.5-PR material but preserving its outstanding electrical energy storage capacity. Successfully accomplishing this goal, we believe that NMC-9.5.5-PR or a material based on NMC9.5.5-PR will be one of the suitable materials to fabricate positive electrodes used in lithium-ion batteries.

Modification of LiMn0·6Fe0·4PO4 lithium-ion battery cathode materials with a fluorine-doped carbon coating

In this study, glucose and NH4F were utilized as sources of carbon and fluorine, respectively, for the synthesis of LiMn0·6Fe0·4PO4 (LMFP) nanoscales. These nanoscales were subsequently modified with varying levels of fluorine-doped carbon through co-precipitation and mechanical ball milling processes. The LMFP, incorporating carbon and varying levels of fluoride ions, exhibit higher specific discharge capacities at 0.2 Cand electrochemical characteristics compared to the original LMFP coated solely with carbon. The inclusion of fluorine-doped carbon in the composite material creates numerous pathways for expeditious electron transfer. Moreover, the partial formation of metal fluoride at the interface between the surface of LMFP and the layer of carbon coating doped with fluorine enhances the reduction in the charge-transfer resistance. The modified ferromanganese phosphate cathode material reveals an outstanding discharge capacity displaying a reversible discharge specific capacity value of 131.73 mA h g−1 at 10C and 154.6 mA h g−1 at 0.2C, due to its unique structure.

Recent advances in surface coating and atomic doping strategies for lithium-ion battery cathodes: implementation approaches and functional mechanisms

Recent advances in surface coating and atomic doping strategies for lithium-ion battery cathodes: implementation approaches and functional mechanisms

Interface chemical reconstruction with residual lithium compounds on nickel-rich cathode by nonstoichiometrical MoO3-x coating enables high stability

The layered lithium nickel-rich cathodes have become one of the most promising candidates for next-generation lithium-ion batteries with high energy density, However, the nickel-rich cathode suffers from a rapid decay of capacity due to their intrinsic instability and undesirably residual lithium compounds originated from LiNiO2 structural changes on the surface, hindering large-scale commercial application. Herein, a continuous and uniform oxygen vacancy enriched-MoO3-x coating was successfully synthesized and reacted residual lithium compounds as a functional layer on the cathode. Such chemically reconstructed coating (Li2MoO4) strategy endows the 1 wt% MoO3-x coated NCA cathode with a fast Li+ ions transport and enhanced structural stability, leading to an outstanding discharge capacity of 214.0 mAh g−1 at 0.1C (1C = 270 mA g−1), a better capacity retention of 80.3 % after 120 cycles at 0.5C, and an excellent high rate capability of 120 mAh g−1 at 5C cycled in voltage range of 2.75 V–4.3 V. This work provides an effective strategy to modulate surface structure towards advanced Ni-rich cathodes for high-performance lithium-ion batteries.

Impact of ball milling on the energy storage properties of LiFePO4 cathodes for lithium-ion batteries

Impact of ball milling on the energy storage properties of LiFePO4 cathodes for lithium-ion batteries

“Acid + Oxidant” Treatment Enables Selective Extraction of Lithium from Spent NCM523 Positive Electrode

With the rapid development of new energy vehicles and energy storage industries, the demand for lithium-ion batteries has surged, and the number of spent LIBs has also increased. Therefore, a new method for lithium selective extraction from spent lithium-ion battery cathode materials is proposed, aiming at more efficient recovery of valuable metals. The acid + oxidant leaching system was proposed for spent ternary positive electrode materials, which can achieve the selective and efficient extraction of lithium. In this study, 0.1 mol L−1 H2SO4 and 0.2 mol L−1 (NH4)2S2O8 were used as leaching acid and oxidant. The leaching efficiencies of Li, Ni, Co, and Mn were 98.7, 30, 3.5, and 0.1%, respectively. The lithium solution was obtained by adjusting the pH of the solution. Thermodynamic and kinetic studies of the lithium leaching process revealed that the apparent activation energy of the lithium leaching process is 46 kJ mol−1 and the rate step is the chemical reaction process. The leaching residue can be used as a ternary precursor to prepare regenerated positive electrode materials by solid-phase sintering. Electrochemical tests of the regenerated material proved that the material has good electrochemical properties. The highest discharge capacity exceeds 150 mAh g−1 at 0.2 C, and the capacity retention rate after 100 cycles exceeds 90%. The proposed new method can extract lithium from the ternary material with high selectivity and high efficiency, reducing its loss in the lengthy process. Lithium replenishment of the delithiation material can also restore its activity and realize the comprehensive utilization of elements such as nickel, cobalt, and manganese. The method combines the lithium recovery process and the material preparation process, simplifying the process and saving costs, thus providing new ideas for future method development.

Enhancing the Cycling and Rate Performance of Ni-Rich Cathodes for Lithium-Ion Batteries by Bulk-Phase Engineering and Surface Reconstruction.

The structural and interfacial instability of Ni-rich layered cathodes LiNi0.9Co0.05Mn0.05O2 (NCM9055) severely hinders their commercial application. In this work, straightforward high-temperature solid-state methods are utilized to successfully synthesize Nb-doped and Li3PO4-coated LiNi0.9Co0.05Mn0.05O2 by combining two niobium sources, NbOPO4·3H2O and Nb2O5, for the first time. Studies indicate that Nb doping enhanced the integrity of the layered structure, and the Li3PO4 coating reduced water absorption on the surface and considerably boosted the durability of the interface. The dual-modified cathode Li(Ni0.9Co0.05Mn0.05)0.985Nb0.015O2@Li3PO4 (NCM-2) exhibits remarkable cycling and rate performance. The initial discharge specific capacity of NCM-2 is 203.33 mAh g-1 at 0.1 C and 196.04 mAh g-1 at 1 C, while the capacity retention after 200 cycles is 91.38% at 1 C, which is much higher than that of pristine NCM9055 (49.96%). In addition, it also provides a superior discharge specific capacity of about 175.63 mAh g-1 even at 5 C. This study emphasizes a feasible approach to enhancing the stability of Ni-rich cathodes at the interfaces and bulk structures.

Enhanced electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathode for lithium ion batteries via a modified calcination process

Nickel (Ni)-rich cathodes with long service life and high energy density are play important role in the rapidly development of lithium ion batteries. However, the rapid development of Ni-rich cathode is still limited by its unstable structure and severely attenuated capacity. Herein, the LiNi0.6Co0.2Mn0.2O2 cathode was obtained from the solid phase method followed by calcination with a low-temperature holding step. The sample (LNCM-3) synthesized with calcination at 250 °C for 6 h and 850 °C for 10 h exhibits higher discharge specific capacity of 194.8 mAh g−1 and 131.0 mAh g−1 at 0.1C and 5C current density, and the capacity retention were 96.2 % and 75.7 % at 1C and 5C after 100 cycles in half cell. The obvious improved electrochemical performances are due to the low-temperature holding step could extend layer spacing and increase the crystalline of materials, which are confirmed by the results of XRD and TEM. Moreover, the full battery assembled with LNCM-3 as the cathode displays a higher specific capacity of 165.8 mAh g−1 at 0.1C and a superior cycling stability of 96.0 % after 100 cycles at 1C rate in the voltage range of 2.7–4.2 V.