High-energy Cathode Materials Research Articles

Cu-substituted Prussian white with low crystal defects as high-energy cathode materials for sodium-ion batteries

Prussian white (PW) has emerged as a promising cathode material for high-energy sodium-ion batteries owing to its high working voltage, high specific capacity, and cost-effectiveness. Nonetheless, its practical utilization is impeded by challenges related to insufficient cycling stability, primarily stemming from poor structural stability due to large defects in the lattice structures and irreversible phase transitions. In this study, we propose a novel strategy to overcome these challenges by substituting the manganese sites of PW with 10 mol% copper. During the synthesis process, substitution with Cu enabled the formation of fewer defects and interstitial water. Cu has no electrochemical redox reactions during the charge-discharge process; so, it showed an initial lower capacity(120 mAh g-1 at 0.1C). However, Cu substitution resulted in a significant improvement in the long-term cycling stability(67.6% at 10C after 500 cycles) by relieving structural stress due to the reversible rhombohedral-to-cubic phase transition. Moreover, the pouch cell (PW-Cu10/hard carbon) exhibits a discharge capacity of 85.4 mAh g−1 and stable cycling retention of 80% at 1.0C after 250 cycles. This work demonstrates a feasible strategy for designing practical Prussian white cathode materials for sodium-ion batteries.

Designing mesostructured iron (II) fluorides with a stable in situ polymer electrolyte interface for high-energy-density lithium-ion batteries

As high-energy cathode materials, conversion-type metal fluorides provide a prospective pathway for developing next-generation lithium-ion batteries. However, they suffer from severe performance decay owing to continuous structural destruction and active material dissolution upon cycling, which worsen at elevated temperatures. Here, we design a novel FeF2 cathode with in situ polymerized solid-state electrolyte systems to enhance the cycling ability of metal fluorides at 60 ​°C. Novel FeF2 with a mesoporous structure (meso-FeF2) improves Li+ diffusion and relieves the volume change that typically occurs during the alternating conversion reactions. The structural stability of the meso-FeF2 cathode is strengthened by an in situ polymerized solid-state electrolyte, which prevents the pulverization and ion dissolution that are inevitable for conventional liquid electrolytes. Under the double action of this in situ polymerized solid-state electrolyte and the meso-FeF2's mesoporous structure, the active material maintains an intact SEI layer and part of the mesoporous structure after long charge–discharge cycling, showing excellent cycling stability at high temperatures.

Two-dimensional V4C3@NiSe2 (Mxene) as high-energy and long-life cathode materials for sustainable aluminum batteries

In this context, we successfully synthesized a nickel diselenide-doped two-dimensional vanadium carbide composite V4C3@NiSe2, which was achieved by etching the V4AlC3 phase using the Louis acid molten salt etching process and subsequently calcining it with selenium. The chemical groups on the V4C3 layer are replaced by selenium, allowing selenium to integrate into the process, thereby increasing energy density and facilitating smoother intercalation of [AlCl4]− ions between these layers, which will reduce material losses during charge and discharge. Due to the interface modification of selenium, the V4C3@NiSe2 battery exhibits excellent conductivity, faster ion diffusion rate, and superior cycling stability. At 1 A g−1, the V4C3@NiSe2 cathode exhibits an impressive initial capacity of up to 636.8 mAh g−1, maintaining a stable capacity of 95 mAh g−1 after about 2700 cycles. In summary, this work proposes a simple synthesis method for high-performance cathode materials such as V4C3@NiSe2, which paves the way for the industrialization of high-performance rechargeable aluminum batteries.

Role of Conducting Polymer in Aqueous Zinc Ion Batteries

Owing to high safety and low cost, aqueous rechargeable zinc-ion batteries (ZIBs) is currently a major research topic. In this study, we propose the microwave-assisted hydrothermal synthesis of polypyrrole (PPy)-coated Na1.1V3O7.9 (P-NVO) nanorods for the first time as a highenergy and high-power cathode material for ZIBs. The highly conductive PPy surface-coating layer is significant to enhance the electronic conductivity and Zn2+ diffusion kinetics, leading to utilize the V3+/V4+/V5+ multiple redox reactions of the NVO cathode in ZIBs. Compared to the NVO cathode, therefore, the P-NVO cathode offers higher discharge capacity, power capability and cycling stability; in particular, PPy coating triggers the full theoretical capacity of the NVO cathode (527 mAh g- 1 with ~ 3 mol Zn insertion per formula unit) and directly reflects a superior energy density of 408 Wh kg-1. Even at a high current density of 6000 mA g- 1, the P-NVO cathode sustains 1000 cycles with almost 100% capacity retention. Galvanostatic intermittent titration technique, cyclic voltammetry, in situ X-ray diffraction, and ex situ X-ray absorption near edge structure analyses are combined to verify the superior Zn2+ storage mechanism of the P-NVO cathode.

Nanocomposite Engineering of High-Capacity Partially Ordered Cathode Materials for Li-Ion Batteries

Understanding the local cation order in the crystal structure and its correlation with cycling performances has promoted the development of high-energy Mn-rich cathode materials for Li-ion batteries, such as Li- and Mn-rich layered cathodes (LMR, e.g., Li1.2Ni0.2Mn0.6O2) that are considered as nanocomposite layered materials with C2/m Li2MnO3-type medium-range order (MRO). Also, Li diffusivity in high-capacity Mn-based disordered rock-salt (DRX) cathodes (e.g., Li1.2Mn0.6Nb0.2O2) was found to be influenced by the short-range order (SRO) of cations, highlighting the criticality of engineering the local cation order in designing high-energy materials. In this presentation, we will discuss the nanocomposite, heterogeneous nature (like MRO found in LMR) of ultrahigh-capacity partially ordered cathodes (e.g., Li1.68Mn1.6O3.7F0.3) made of distinct domains of spinel-, DRX- and layered-like phases, which is different from conventional single-phase DRX cathodes. This multi-scale understanding of ordering informs engineering the nanocomposite material via Ti doping, altering the intra-particle characteristics to increase the content of the rock-salt phase and heterogeneity within a particle. This strategy greatly improves the reversibility of Mn- and O-redox processes to enhance the cycling stability of the partially ordered DRX cathodes (nearly ~30 % improvement of capacity retention). Overall, our work sheds light on the importance of nanocomposite engineering to develop ultrahigh-performance, low-cost Li-ion cathode materials.

Na3VMn0.5Ti0.5(PO4)3/C with active Na+ hopping sites for high-rate and durable sodium-ion batteries

This study established the carbon-coated Na3VMn0.5Ti0.5(PO4)3/C (NVMTP/C) as a high-energy cathode material of the NASICON family for next-generation sodium-ion batteries (SIBs). When subjected to electrochemical sodium storage testing, the NVMTP/C cathode provided a stable specific capacity of 160.3 mAh g-1 with three electron reactions (average working voltage ∼3.4 V) during the Na+ (de)insertion routine, achieving a superior energy output of 544 Wh kg−1 among the NASICON family of SIBs. Benefiting from the characteristic NASICON structure and established multiple redox couples, the cathode delivered excellent rate capability (82 mAh g-1 at 17 C, 1 C = 176 mAh g-1), in addition to excellent cycling permanence at low and high current surges (104 mAh g-1 after 500 cycles at 0.85 C and 84 mAh g-1 after 3000 cycles at 11.34 C, respectively). Computational studies based on first principle calculations and density of states (DoS) attributed the superior electrochemical properties of NVMTP/C cathode to its substantial Na+ hopping sites facilitating the unhindered multi-electron transfer reactions (V2+/3+, V3+/4+, Ti3+/4+, and V4+/5+) reversibly at their respective redox potentials. The detailed DoS analysis revealed that the varying electronic configuration due to the co-swapping of Ti and Mn significantly uplifts the electronic conductivity of the NVMTP/C cathode. Further calculation studies clearly indicate lower activation energy for active Na+ hopping and hence faster Na-diffusion thus suggesting that the present NVMTP/C cathode can have definite commercial prospects.

Polyaniline modified waste‐derived graphene/sulfur nanocomposite cathode for lithium–sulfur batteries

AbstractReduction of plastic wastes in the environment and solving the energy demands from renewable sources are two important challenging tasks of this century. Modern day lives are highly entangled with polymers, however handling the huge wastes from plastics is also a serious concern. Translating the plastic wastes to useful products such as graphene can be an alternative for nonbiodegradable polymer wastes. Efficient energy storage devices, for instance, batteries are required for storing the renewable energies. With the aim of regulating these issues, we report, for the first time, the preparation of high energy cathode materials from the nanocomposites (NCs) having polyaniline (PANI), waste‐derived graphene (WDG) derived from plastic waste and sulfur (S) for Li–S battery applications. We compare the electrochemical properties of cathodes derived from WDG/S and WDG/PANI/S in Li–S batteries. The specific discharge capacity of WDG/PANI/S at 0.1 C was obtained to be 880 mAhg−1 normalized to sulfur mass at 1st cycle, 472 mAhg−1 at 100th cycle, and 400 mAhg−1 at 160th cycle. The rate capability is also found to be good at C‐rates less than 0.5 C. We found that WDG/PANI/S showed decent electrochemical properties when compared with the reference sample, WDG/S at similar sulfur loading without PANI modification.

Cr-doped Na3V2(PO4)3@C enables high-capacity with V2+/V5+ reaction and stable sodium storage

Due to its abundant sodium content and low cost, sodium-ion battery (SIB) has become an effective substitute and supplement for lithium-ion batteries, which has a broad development prospect in large-scale energy storage systems. Na-super-ionic conductor (NASICON) structural materials have stable 3D skeleton structures and open Na+ transport channels, which is a very promising SIB cathode material. But in the typical NASICON material Na3V2(PO4)3 (NVP), the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window, which limits the further improvement of battery performance. In this work, we report another NASICON structured Na3V4/3Cr2/3(PO4)3@C (NVCP@C), which is obtained by Cr-doped NVP through spray drying. By taking full advantage of the voltage platforms of V5+/4+, V4+/3+, and V3+/2+ in the window of 1.5–4.4 V, NVCP@C delivered a high discharge capacity (175 mAh g–1) and durable cyclability (86% capacity retention for 2000 cycles). In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge processes. When coupled with Na+ pre-embedded hard carbon (HC), the assembled NVCP@C//HC full cell delivers a high capacity (105 mAh g–1) and long cycling performance (70% after 1000 cycles). This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.

Trends in Automotive Battery Cell Design: A Statistical Analysis of Empirical Data

Lithium-ion (Li-ion) batteries have become the preferred power source for electric vehicles (EVs) due to their high energy density, low self-discharge rate, and long cycle life. Over the past decade, technological enhancements accompanied by massive cost reductions have enabled the growing market diffusion of EVs. This diffusion has resulted in customized and cost-effective Li-ion battery cell designs tailored to automotive requirements. This study describes design trends in Li-ion batteries from the pack to the electrode level based on empirical data, including pack energy, cell capacity, outer cell dimensions and formats, energy density, specific energy, and electrode properties, such as active material selection, porosities, and component thicknesses. Market share-weighted findings imply several trends, such as (1) increasing cell dimensions, with the longest cells reaching 500 mm (pouch) and almost 1000 mm (prismatic) in 2021, (2) increasing differentiation between either high-energy or low-cost cathode and anode materials, and (3) increasing cell energy, equivalent to gaining about 100% (energy density) and 70% (specific energy) compared to the 2010 and 2021 averages. Despite these improvements, this study finds that the widespread market diffusion of the latest cell technologies proceeds slower than industry announcements suggest and that several well-known, literature-proofed potentials are not yet fully exploited.

Suppressing Universal Cathode Crossover in High-Energy Lithium Metal Batteries via a Versatile Interlayer Design.

The universal cathode crossover such as chemical and oxygen has been significantly overlooked in lithium metal batteries using high-energy cathodes which leads to severe capacity degradation and raises serious safety concerns. Herein, a versatile and thin (≈25 μm) interlayer composed of multifunctional active sites was developed to simultaneously regulate the Li deposition process and suppress the cathode crossover. The as-induced dual-gradient solid-electrolyte interphase combined with abundant lithiophilic sites enable stable Li stripping/plating process even under high current density of 10 mA cm-2 . Moreover, X-ray photoelectron spectroscopy and synchrotron X-ray experiments revealed that N-rich framework and CoZn dual active sites can effectively mitigate the undesired cathode crossover, hence significantly minimizing Li corrosion. Therefore, assembled lithium metal cells using various high-energy cathode materials including LiNi0.7 Mn0.2 Co0.1 O2 , Li1.2 Co0.1 Mn0.55 Ni0.15 O2 , and sulfur demonstrate significantly improved cycling stability with high cathode loading.

Stabilized electrode phase by prelithiating V2O5 cathode materials for high-specific energy thermal batteries

Vanadium pentoxide (V2O5) is an attractive high-energy cathode material for thermal batteries but is limited by the high solubility and tendency to react with halogenic molten salt. LixV2O5 (0 < x ≤ 1) are expected to take the place of V2O5 as the promising cathode materials in thermal batteries. In this work, LixV2O5 were successfully synthesized by the high-efficiency and low-cost method, which uses the molten salt as lithium source and through a brief-time sintered process (900 °C for 15 s). LixV2O5/molten salt electrode with CNTs conductive agent exhibits an original discharge voltage with 2.51 V and a specific capacity up to 309.46 mA h g−1. The high chemical stabilization between LixV2O5 and molten salt which could increase interfacial structure stabilization and improve the transmission rate of Li+. Besides, CNTs could build the continuous electron transport channels in active cathode inter-particles and improve the utilization rate of LixV2O5. This paper not only prepares the LixV2O5 cathode materials with high specific capacity via a simple method, but also provides insights into the phase evolution process of V2O5 based cathode electrodes during discharge process of thermal batteries.

Integrating surface structure via triphenyl phosphate treatment to stabilize Li-rich Mn-based cathode materials

Li-rich Mn-based layered oxides (LLOs) have emerged as one of the most promising cathode materials for the next-generation lithium-ion batteries (LIBs) because of their high energy density, high specific capacity, and environmental friendliness. These materials, however, have drawbacks such as capacity degradation, low initial coulombic efficiency (ICE), voltage decay, and poor rate performance due to irreversible oxygen release and structural deterioration during cycling. Herein, we present a facile method of triphenyl phosphate (TPP) surface treatment to create an integrated surface structure on LLOs that includes oxygen vacancies, Li3PO4, and carbon. When used for LIBs, the treated LLOs show an increased initial coulombic efficiency (ICE) of 83.6% and capacity retention of 84.2% at 1C after 200 cycles. It is suggested that the enhanced performance of the treated LLOs can be attributed to the synergetic functions of each component in the integrated surface, such as the oxygen vacancy and Li3PO4 being able to inhibit the evolution of oxygen and accelerate the transport of lithium ions, while the carbon layer can restrain undesirable interfacial side reactions and reduce the dissolution of transition metals. Furthermore, electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) prove an enhanced kinetic property of the treated LLOs cathode, and ex-situ X-ray diffractometer shows a suppressed structural transformation of TPP-treated LLOs during the battery reaction. This study provides an effective strategy for constructing an integrated surface structure on LLOs to achieve high-energy cathode materials in LIBs.

Mg Substitution Induced TM/Vacancy Disordering and Enhanced Structural Stability in Layered Oxide Cathode Materials.

Anionic redox is an effective way to increase the capacity of the cathode materials. Na2Mn3O7 [Na4/7[Mn6/7□1/7]O2, □ for the transition metal (TM) vacancies] with native and ordered TM vacancies can conduct a reversible oxygen redox and be a promising high-energy cathode material for sodium-ion batteries (SIBs). However, its phase transition at low potentials (∼1.5 V vs Na+/Na) induces potential decays. Herein, magnesium (Mg) is doped on the TM vacancies to form a disordered Mn/Mg/□ arrangement in the TM layer. The Mg substitution suppresses the oxygen oxidation at ∼4.2 V by reducing the number of the Na-O-□ configurations. Meanwhile, this flexible disordering structure inhibits the generation of the dissolvable Mn2+ ions and mitigates the phase transition at ∼1.6 V. Therefore, the Mg doping improves the structural stability and its cycling performance in 1.5-4.5 V. The disordering arrangement endows Na0.49Mn0.86Mg0.06□0.08O2 with a higher Na+ diffusivity and improved rate performance. Our study reveals that oxygen oxidation is highly dependent on the ordering/disordering arrangements in the cathode materials. This work provides insights into the balance of anionic and cationic redox for enhancing the structural stability and electrochemical performance in the SIBs.

Locally Concentrated Ionic Liquid Electrolytes for Lithium-Metal Batteries.

Non-flammable ionic liquid electrolytes (ILEs) are well-known candidates for safer and long-lifespan lithium metal batteries (LMBs). However, the high viscosity and insufficient Li+ transport limit their practical application. Recently, non-solvating and low-viscosity co-solvents diluting ILEs without affecting the local Li+ solvation structure are employed to solve these problems. The diluted electrolytes, i.e., locally concentrated ionic liquid electrolytes (LCILEs), exhibiting lower viscosity, faster Li+ transport, and enhanced compatibility toward lithium metal anodes, are feasible options for the next-generation high-energy-density LMBs. Herein, the progress of the recently developed LCILEs are summarised, including their physicochemical properties, solution structures, and applications in LMBs with a variety of high-energy cathode materials. Lastly, a perspective on the future research directions of LCILEs to further understanding and achieve improved cell performances is outlined.

Surface Engineering Stabilizes Rhombohedral Sodium Manganese Hexacyanoferrates for High-Energy Na-Ion Batteries.

The rhombohedral sodium manganese hexacyanoferrate (MnHCF) only containing cheap Fe and Mn metals was regarded as a scalable, low-cost, and high-energy cathode material for Na-ion batteries. However, the unexpected Jahn-teller effect and significant phase transformation would cause Mn dissolution and anisotropic volume change, thus leading to capacity loss and structural instability. Here we report a simple room-temperature route to construct a magical Cox B skin on the surface of MnHCF. Benefited from the complete coverage and the buffer effect of Cox B layer, the modified MnHCF cathode exhibits suppressed Mn dissolution and reduced intergranular cracks inside particles, thereby demonstrating thousands-cycle level cycling lifespan. By comparing two key parameters in the real energy world, i.e., cost per kilowatt-hours and cost per cycle-life, our developed Cox B coated MnHCF cathode demonstrates more competitive application potential than the benchmarking LiFePO4 for Li-ion batteries.

Regulating the Potential of Anion Redox to Reduce the Voltage Hysteresis of Li-Rich Cathode Materials.

Layered Li-rich oxides (LROs) that exhibit anionic and cationic redox are extensively studied due to their high energy storage capacities. However, voltage hysteresis, which reduces the energy conversion efficiency of the battery, is a critical limitation in the commercial application of LROs. Herein, using two Li2RuO3 (LRO) model materials with C2/c and P21/m symmetries, we explored the relationship between voltage hysteresis and the electronic structure of Li2RuO3 by neutron diffraction, in situ X-ray powder diffraction, X-ray absorption spectroscopy, macro magnetic study, and electron paramagnetic resonance (EPR) spectroscopy. The charge-transfer band gap of the LRO cathode material with isolated eg electron filling decreases, reducing the oxidation potential of anion redox and thus displaying a reduced voltage hysteresis. We further synthesized Mn-based Li-rich cathode materials with practical significance and different electron spin states. Low-spin Li1.15Ni0.377Mn0.473O2 with isolated eg electron filling exhibited a reduced voltage hysteresis and high energy conversion efficiency. We rationalized this finding via density functional theory calculations. This discovery should provide critical guidance in designing and preparing high-energy layered Li-rich cathode materials for use in next-generation high-energy-density Li-ion batteries based on anion redox activity.

Nanocomposite Engineering of a High-Capacity Partially Ordered Cathode for Li-Ion Batteries.

Understanding the local cation order in the crystal structure and its correlation with electrochemical performances has advanced the development of high-energy Mn-rich cathode materials for Li-ion batteries, notably Li- and Mn-rich layered cathodes (LMR, e.g., Li1.2 Ni0.13 Mn0.54 Co0.13 O2 ) that are considered as nanocomposite layered materials with C2/m Li2 MnO3 -type medium-range order (MRO). Moreover, the Li-transport rate in high-capacity Mn-based disordered rock-salt (DRX) cathodes (e.g., Li1.2 Mn0.4 Ti0.4 O2 ) is found to be influenced by the short-range order of cations, underlining the importance of engineering the local cation order in designing high-energy materials. Herein, the nanocomposite is revealed, withaheterogeneous nature (like MRO found in LMR) of ultrahigh-capacity partially ordered cathodes (e.g., Li1.68 Mn1.6 O3.7 F0.3 ) made of distinct domains of spinel-, DRX- and layered-like phases, contrary to conventional single-phase DRX cathodes. This multi-scale understanding of ordering informs engineering the nanocomposite material via Ti doping, altering the intra-particle characteristics to increase the content of the rock-salt phase and heterogeneity within a particle. This strategy markedly improves the reversibility of both Mn- and O-redox processes to enhance the cycling stability of the partially ordered DRX cathodes (nearly ≈30% improvement of capacity retention). This work sheds light on the importance of nanocomposite engineering to develop ultrahigh-performance, low-cost Li-ion cathode materials.

Enhancing the interfacial stability of all-solid-state high-energy sodium-ion batteries by coating materials: First principles calculations

All-solid-state batteries are promising next-generation batteries owing to their enhanced safety and high energy density. Recently, all-solid-state sodium-ion batteries have broadly investigated owing to low price and abundance of sodium. Various types of solid electrolytes (SEs) exhibiting high ionic conductivities have been investigated for all-solid-state Na-ion batteries. However, a few studies have been reported for the interfacial stability of sodium SEs against high-energy cathode materials. In this study, we systematically investigated the interfacial stability between ten sodium superionic conductors and 16 high-energy oxide cathode materials. The calculation results indicated that sodium sulfide and selenide SEs generally exhibit chemical incompatibility with cathode materials, suggesting that interfacial coating should be employed to alleviate the interfacial reaction. We utilized high-throughput screening process to identify promising coating materials between sodium SEs and cathode materials. Eight compounds from 7,398Na-containing compounds were screened as promising coating materials, which considerably reduced the chemical reactivity at the interface. The findings of this study can provide design strategies for the all-solid-state sodium-ion batteries.

Uniform P2-K0.6CoO2 Microcubes as a High-Energy Cathode Material for Potassium-Ion Batteries

Layered transition-metal (TM) oxides have drawn ever-growing interest as positive electrode materials in potassium-ion batteries (PIBs). Nevertheless, the practical implementation of these positive electrode materials is seriously hampered by their inferior cyclic property and rate performance. Reported here is a self-templating strategy to prepare homogeneous P2-K0.6CoO2 (KCO) microcubes. Benefiting from the unusual microcube architecture, the interface between the electrolyte and the active material is considerably diminished. As a result, the KCO microcubes manifest boosted electrochemical properties for potassium storage including large reversible capacity (87.2 mAh g-1 under 20 mA g-1), superior rate performance, and ultralong cyclic steady (an improved capacity retention of 86.9% under 40 mA g-1 after 1000 cycles). More importantly, the fabrication approach can be effectively extended to prepare other layered TM oxide (P3-K0.5MnO2, P3-K0.5Mn0.8Fe0.2O2, P2-K0.6Co0.67Mn0.33O2, and P2-K0.6Co0.66Mn0.17Ni0.17O2) microcubes and nonlayered TM oxide (KFeO2) microcubes.

A gradient oxy-thiophosphate-coated Ni-rich layered oxide cathode for stable all-solid-state Li-ion batteries

High-energy Ni-rich layered oxide cathode materials such as LiNi0.8Mn0.1Co0.1O2 (NMC811) suffer from detrimental side reactions and interfacial structural instability when coupled with sulfide solid-state electrolytes in all-solid-state lithium-based batteries. To circumvent this issue, here we propose a gradient coating of the NMC811 particles with lithium oxy-thiophosphate (Li3P1+xO4S4x). Via atomic layer deposition of Li3PO4 and subsequent in situ formation of a gradient Li3P1+xO4S4x coating, a precise and conformal covering for NMC811 particles is obtained. The tailored surface structure and chemistry of NMC811 hinder the structural degradation associated with the layered-to-spinel transformation in the grain boundaries and effectively stabilize the cathode|solid electrolyte interface during cycling. Indeed, when tested in combination with an indium metal negative electrode and a Li10GeP2S12 solid electrolyte, the gradient oxy-thiophosphate-coated NCM811-based positive electrode enables the delivery of a specific discharge capacity of 128 mAh/g after almost 250 cycles at 0.178 mA/cm2 and 25 °C.