Prelithiation Strategy Research Articles

Molecular Engineering Chemical Pre-lithiation Reagent with Low Redox Potential for Graphite Anode Enables High Coulombic Efficiency.

Graphite (Gr) is a low-cost and high-stability anode for lithium-ion batteries (LIBs). However, Gr anode exhibits an obstinate drawback of low initial Coulombic efficiency (ICE), owing to the active lithium loss for the solid electrolyte interphase (SEI) layer. Herein, a straightforward and effective chemical pre-lithiation strategy is proposed to compensate for the lithium loss. A molecular engineering phenanthrene-based lithium-arene complex (Ph-based LAC) reagent is designed by density functional theory (DFT) calculations. The engineering Ph-based reagent enhances the stability of the π-electron system and the electron-donating capacity, resulting in a reduced redox potential to facilitate lithium transfer. The electrochemical distinct of the Ph-based reagent is illustrated, the prelithiation process in a low Li-insertion platform, and the lithiation degree is controllable with the dipping time (ICE = 102%, 3min). Notably, a denser and homogeneous SEI layer has pre-formed to enhance the Li+ transport and interface stability. Moreover, the lithium-ion full batteries assemble with LiFePO4 and NCM811 cathode, which exhibits high ICE (96.5% and 90.3%) and energy density (310 and 333Whkg-1). These findings present a facile and controllable pre-lithiation strategy to compensate for the lithium of LIBs, providing new valuable insights into the design and optimization of battery manufacture.

Enhanced Lithium Extraction from Brines: Prelithiation Effect of FePO4 with Size and Morphology Control.

Extracting lithium resources from seawater and brine can promote the development of the new energy materials industry. The electrochemical method is green and efficient. Iron phosphate (FePO4) crystal, with its 1D ion channel, holds significant potential as a primary lithium extraction electrode material. Li+ encounters a substantial concentration disadvantage in brines, and the co-intercalation of Na+ diminishes Li+ selectivity. To address this issue, this work enhances the energy barrier for Na+ insertion through prelithiation strategies applied to the 1D channels of FePO4 crystal, thereby improving Li+ selectivity, and further investigating the prelithiation effect with particle size and morphology control. The results indicate that the Li(4C-40%)FePO4// Activated carbon(AC) system enhances selectivity of lithium. The Li(4C-40%)FePO4 with size diameter of 2500nm demonstrates an energy consumption of 0.79Whmol-1 and a purity of 97.94% for lithium extraction at a unit lithium extraction of 5.93mmolg-1 in simulated brine. Li(4C-40%)FePO4-nanoplates demonstrate the most optimal lithium extraction performance among the three morphologies due to their lamellar structure's short ion diffusion path in the [010] channel, favoring Li+ diffusion. The diffusion energy barriers of Li+ and Na+ are calculated using Density Functional Theory (DFT) before and after prelithiation, showing good agreement with experimental results.

Small‐Molecule Polycyclic Aromatic Hydrocarbons as Exceptional Long‐Cycle‐Life Li‐Ion Battery Anode Materials

The growing demand for cost‐effective and sustainable energy‐storage solutions has spurred interest in novel anode materials for lithium‐ion batteries (LIBs). In this study, the potential of small‐molecule polycyclic aromatic hydrocarbons (SMPAHs) as promising candidates for LIB anodes is explored. Through a comprehensive experimental approach involving electrode fabrication, material characterization, and electrochemical testing, the electrochemical performance of SMPAHs, including naphthalene, biphenyl, 9,9‐dimethylfluorene, phenanthrene, p‐terphenyl, and pyrene (Py), is thoroughly investigated. In the results, the impressive cycle stability, high specific capacity, and excellent rate capability of the SMPAH electrode are revealed. Additionally, a direct contact prelithiation strategy is implemented to enhance the initial Coulombic efficiency (ICE) of SMPAH anodes, yielding significant improvements in the ICE and cycle stability. Computational simulations provide valuable insights into the electrochemical behavior and lithium‐storage mechanisms of SMPAHs, confirming their potential as effective anode materials. The simulations reveal favorable lithium adsorption sites, the predominant storage mechanisms, and the dissolution mechanism of Py through computational calculations. Overall, in this study, the promise of SMPAHs is highlighted as sustainable anode materials for LIBs, advancing energy‐storage technologies toward a greener future.

Enhancing micro-scale SiOx anode durability: Electro-mechanical strengthening of binder networks via anchoring carbon nanotubes with carboxymethyl cellulose

With the increasing prevalence of lithium-ion batteries (LIBs) applications, the demand for high-capacity next-generation materials has also increased. SiOx is currently considered a promising anode material due to its exceptionally high capacity for LIBs. However, the significant volumetric changes of SiOx during cycling and its initial Coulombic efficiency (ICE) complicate its use, whether alone or in combination with graphite materials. In this study, a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiOx blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker. In addition, a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiOx. The combination of these two strategies increased the CE of SiOx from 74% to 87% and effectively mitigated its volume expansion in the graphite/SiOx blended electrode, resulting in an efficient electron-conductive binder network. This led to a remarkable capacity retention of 94% after 30 cycles, even under challenging conditions, with a high capacity of 550 mA h g−1 and a current density of 4 mA cm−2. Furthermore, to validate the feasibility of utilizing prelithiated SiOx anode materials and the conductive binder network in LIBs, a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used. This cell demonstrated a ∼27.3% increase in discharge capacity of the first cycle (∼185.7 mA h g−1) and exhibited a cycling stability of 300 cycles. Thus, this study reports a simple, feasible, and insightful method for designing high-performance LIB electrodes.

A high-efficiency pre-lithiation strategy for Li-ion capacitor achieved by the synergistic effect of pre-lithiation and solid electrolyte interface film modification

The cathodic pre-lithiation process, currently considered the most feasible resolution to address the irreversible depletion of Li+ in dual carbon-based lithium-ion capacitors (LICs), encounters obstacles in widespread adoption due to its substantial dosage requirement, rising decomposition potential and the damage related to its decomposition residues. Hence, in this study, the successful utilization of Li2NiO2 for LIC pre-lithiation is accomplished, leveraging the synergistic effect between Li2NiO2 and lithium difluoro oxalate borate (LiDFOB). It's noteworthy that the full capacitor, entirely composed of commercial materials (activated carbon/hard carbon) and supplemented with 20 wt% LNO +2 wt% LiDFOB, exhibits remarkable energy densities of 98.53 Wh kg−1 at a power density of 31 W kg−1 and 19 Wh kg−1 at a power density of 4.65 kW kg−1. Moreover, the full capacitor displays commendable performance, demonstrating superior capacitive behavior and excellent high-current cycling proficiency. Besides, electrochemical evaluations and structural analyses unveil that LiDFOB, via solid electrolyte interface (SEI) modification, enhances the utilization of Li+ sourced from Li2NiO2 thus avoiding the abuse of pre-lithiation reagents, while the LNO decomposition products contribute substantially to additional capacitance. The synergistic effect of pre-lithiation reagent and SEI modification underpin the outstanding performance witnessed in the full capacitor.

Rational Design of LixSiOy-Based Pre-SEI through Thermal-Evaporated Li-Metal Prelithiated SiOx Anode Enabling Extremely Stable and High-Rate Lithium Microbatteries

Recently, silicon oxides families (SiOx) have been commercialized as high capacity anode materials growing rapidly owing to their natural resource abundance and low-cost.(1) However, both the poor electron/ionic conductivity, and quite low initial coulombic efficiency (ICE) (normally < 60%) limits the further development into next generation SiOx anodes. (2) To address these two critical issues, various pre-lithiation strategies have emerged and systematically investigated with significant progress.(3, 4) Here, we provide a facile approach to prelithiate SiOx films by optimizing RF power and precisely controlling Li-metal deposition to overcome the current challenges of SiOx anodes. We found a strong correlation between the surface chemical state of SiOx and the pre-formation of LixSiOy SEI layers. The optimal prelithiation strategy achieves remarkable rate performance of 72.8% at 20C, and extremely excellent long-term cycling performance of 54.2% over 5000 cycles at 10C. This study significantly promotes SiOx-based anodes development, offering a promising strategy for extreme fast-charging and long-term stability not only overcoming the limitations in microbattery but scalable to practical electrodes.Reference: Q. Mai, Chem. Soc. Rev., 48, 285 (2019). M. L. Jiao, Y. F. Wang, C. L. Ye, C. Y. Wang, W. K. Zhang and C. Liang, J. Alloy. Compd., 842, 21 (2020). R. M. Zhan, X. C. Wang, Z. H. Chen, Z. W. Seh, L. Wang and Y. M. Sun, Adv. Energy Mater., 11, 20 (2021). X. Q. Min, G. J. Xu, B. Xie, P. Guan, M. L. Sun and G. L. Cui, Energy Storage Mater., 47, 297 (2022).

Impact of Electrolyte on Direct-Contact Prelithiation of Silicon-Graphite Anodes in Lithium-Ion Cells with High-Nickel Cathodes.

Silicon-based anodes offer high specific capacities to enhance the energy density of lithium-ion batteries, but are severely hindered by the immense volume expansion and subsequent breakage of the solid-electrolyte-interphase (SEI) during cycling. Herein, we utilize an effective strategy, known as direct-contact prelithiation, to mitigate the challenges associated with expansion and surface instability in SiOx/graphite (SG) anodes. It involves introducing lithium into the anode via physical contact with lithium metal and electrolyte before cycling. Prelithiation of SG anodes with an advanced localized high-concentration electrolyte is shown to develop a mechanically robust artificial SEI that tolerates better the electrode volume expansion. The modified SG anode paired with the high-Ni cathode LiNi0.90Mn0.05Co0.05O2 delivers a high initial capacity of 191 mA h g-1 with 80% capacity retention over 150 cycles, compared to 46% retention with a conventional electrolyte. The bolstered SEI layer with reduced surface reactivity is due to the reduced electrolyte consumption and regulated SEI formation during cycling. Furthermore, the advanced electrolyte and fortified SG anode help reduce cathode degradation, transition-metal dissolution, and loss of active lithium. This study highlights viable prelithiation strategies to stabilize Si-based anodes for high-energy-density batteries through electrolyte design.

SiOx-Rich Electrode Directly Optimized Using Key Formulation Parameters

The use of key parameters of the SiOx/graphite electrode formulation, and their critical values, makes it possible, without any trial-and-error type experimentation, to identify optimal electrode formulations for different SiOx/graphite mass ratios ranging up to 40:60. From the first attempt, electrodes presenting good cyclability at high surface capacity of 5.2 mA h cm−2 were formulated, reaching for example more than 93% capacity retention after 60 cycles in a full cell, with an electrolyte rich in FEC and EC-free, however with a prelithiation strategy. With a positive electrode based on NMC811, the gains in volumetric energy and power density are + 18 and + 28% compared to graphite, considering only the electrode volumes. The principle of using the key electrode formulation parameters introduced here is expected to accelerate and facilitate the optimization of electrode formulations.

Dual-Carbon Phase-Encapsulated Prelithiated SiOx Microrod Anode for Lithium-Ion Batteries.

Among silicon-based anode family for Li-ion battery technology, SiOx, a nonstoichiometric silicon suboxide holds the potential for significant near-term commercial impact. In this context, this study mainly focuses on demonstrating an innovative SiOx@C anode design that adopts a pre-lithiation strategy based on in situ pyrolysis of Li-salt of silsesquioxane trisilanolate without the need for lithium metal or active lithium compounds and creates dual carbon encapsulation of SiOC nanodomains by simply one-step thermal treatment. This ingenious design ensures the pre-lithiation process and pre-lithiation material with high-environmental stability. Moreover, phenyl-rich organosiloxane clusters and polyacrylonitrile polymers are expected to serve as internal and external carbon source, respectively. The formation of an interpenetrating and continuous carbon matrix network would not only synergistically offer an improved electrochemical accessibility of active sites but also alleviate the volume expansion effect during cycling. As a result, this new type of anode delivered a high reversible capacity, remarkable cycle stability as well as excellent high-rate capability. In particular, the L2-SiOx@C material has a high initial coulomb efficiencof 80.4% and, after 500 cycles, a capacity retention as high as 97.5% at 0.5 A g-1 with a reversible specific capacity of 654.5mA h g-1.

Sustainable Prelithiation Strategy: Enhancing Energy Density and Lifespan with Ultrathin Li‐Mg‐Al Alloy Foil

AbstractPrelithiation is a well‐established strategy for enhancing battery energy density. However, traditional prelithiation approaches have primarily addressed compensating for the initial active lithium loss (ALL) while overlooking the ALL during extended cycling. In response, a novel method is introduced by increasing the prelithiation degree and pre‐storing stable LiCx within the anode. This innovation facilitates sustainable lithium replenishment, resulting in a significant improvement in battery cycle life and energy density. Moreover, challenges associated with using pure Li foils to realize this strategy in contact prelithiation are revealed, such as difficulties in thinning to less than 5 µm, and the loss of the electronic pathway during prelithiation, resulting in low lithium utilization rates and numerous residues. Additionally, the significantly accelerated capacity fading caused by these residues, typically emerging after hundreds of cycles, has been overlooked. To overcome these challenges, an ultrathin Li‐Mg‐Al alloy foil is developed with significantly improved mechanical properties and delithiation behavior. During prelithiation, the 96Li2Mg2Al alloy maintains a complete film structure with numerous micropores, avoiding randomly distributed debris. This structure ensures high utilization, unimpeded electronic pathways, and efficient electrolyte filtration. By employing a 5‐µm 96Li2Mg2Al foil for sustainable prelithiation, a substantial improvement in energy density is achieved and tripled the battery's lifespan.

Enhancing Electrochemical Stability of Silicon-Carbon and NMC based Lithium-Ion Batteries through the Synergistic Impact of Charge Balance and Direct-Contact Pre-Lithiation Strategy

The commercial feasibility of silicon (Si) anodes (≥ 30%) in full-cell systems is constrained by poor cyclic stability and capacity balancing due to continuous active lithium (Li) consumption in each cycle. We proposed a capacity balancing approach by adding additional Li at the cathode side (i.e., ratio of capacity at negative to positive electrode (N/P) ∼ 0.9) and anode side (i.e., pre-lithiated Si) before full-cell fabrication. This approach provided a capacity-balanced full-cell with 91.7% of initial Coulombic efficiency (ICE) and stability up to 50 cycles. In-situ electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analysis have been utilized to examine the interface of bare and balanced full cells. In a large format cell, electrolyte wettability is an issue and it has been investigated even at high temperature (50 °C). The post-cycle investigation also indicates the Si particles retained their integrity after cycling. A 110 mAh pouch cell has been constructed, and the pouch cell demonstrated exceptional cyclic stability up to 200 cycles, with a capacity retention of 83.2% at a current rate of 0.1 C. These findings present a capacity balancing approach for high-loading silicon-based anodes that eventually can scale up to high-quality and long-cycle life lithium-ion batteries.

High-Energy SiO-Sulfur Battery with Preloaded Li3N in a Cathode as a Lithiation Reagent.

The practical use of lithium-sulfur batteries faces the "shuttle effect" and lithium dendrite growth. Employing SiO instead of Li metal can fundamentally solve the above problems. Nevertheless, selecting a convenient prelithiation method is essential for normal operation of the battery system. Hence, this work proposed a novel SiO-sulfur battery with preloaded Li3N in a cathode as a prelithiation reagent, which can thoroughly solve the dendrite problem and the side reaction with polysulfides of lithium anode. The S@KB-Li3N vs SiO full cell can obtain a high specific capacity of 790 mAh g-1 after the activation process and be maintained at 478 mAh g-1 after 100 cycles. Our design will provide a new prelithiation strategy for a high-specific-energy SiO-sulfur battery system.

Overcoming low initial coulombic efficiencies of Si anodes through prelithiation in all-solid-state batteries

All-solid-state batteries using Si as the anode have shown promising performance without continual solid-electrolyte interface (SEI) growth. However, the first cycle irreversible capacity loss yields low initial Coulombic efficiency (ICE) of Si, limiting the energy density. To address this, we adopt a prelithiation strategy to increase ICE and conductivity of all-solid-state Si cells. A significant increase in ICE is observed for Li1Si anode paired with a lithium cobalt oxide (LCO) cathode. Additionally, a comparison with lithium nickel manganese cobalt oxide (NCM) reveals that performance improvements with Si prelithiation is only applicable for full cells dominated by high anode irreversibility. With this prelithiation strategy, 15% improvement in capacity retention is achieved after 1000 cycles compared to a pure Si. With Li1Si, a high areal capacity of up to 10 mAh cm–2 is attained using a dry-processed LCO cathode film, suggesting that the prelithiation method may be suitable for high-loading next-generation all-solid-state batteries.

Electrocatalytic Mechanism and Sabatier Principle in C2N-Supported Atomically Dispersed Catalysts for the Sulfur Reduction Reaction in Lithium-Sulfur Batteries.

The sluggish kinetics of the sulfur reduction reaction (SRR) impedes the practical application of lithium-sulfur batteries (LSBs). Electrocatalysts are necessary to expedite the conversion of polysulfides. Here, we systematically investigate the chemical mechanisms and size dependence of catalytic activities toward the SRR from Li2S4 to Li2S on single-, double-, and triple-atom catalysts supported on C2N (Mn@C2N, where M is a 3d transitional metal and n = 1-3) as model systems by using first-principles calculations and a comprehensive electrocatalytic model. Our results reveal that the adsorption strength of the LiS• intermediate is identified as an optimal descriptor for catalytic activity. M1@C2N exhibits superior stability and exceptional activity compared to those of the other two catalyst types. Cu1@C2N exhibits the lowest overpotential of 0.426 V. Li embedding or a prelithiation strategy verifies the therein Sabatier principle. This work emphasizes the precise control of the active site structure and microenvironment in catalytic SRR and offers guidance for the design of electrocatalysts for metal-sulfur batteries.

Solution-Based Deep Prelithiation for Lithium-Ion Capacitors with High Energy Density.

Lithium-ion capacitors (LICs) exhibit superior power density and cyclability compared to lithium-ion batteries. However, the low initial Coulombic efficiency (ICE) of amorphous carbon anodes (e.g., hard carbon (HC) and soft carbon (SC)) limits the energy density of LICs by underutilizing cathode capacity. Here, a solution-based deep prelithiation strategy for carbon anodes is applied using a contact-ion pair dominant solution, offering high energy density based on a systematic electrode balancing based on the cathode capacity increased beyond the original theoretical limit. Increasing the anode ICE to 150% over 100%, the activated carbon (AC)capacity is doubled by activating Li+ cation storage, which unleashes rocking-chair LIC operation alongside the dual-ion-storage mechanism. The increased AC capacity results in an energy density of 106.6Wh kg-1 AC+SC, equivalent to 281% of that of LICs without prelithiation. Moreover, this process lowers the cathode-anode mass ratio, reducing the cell thickness by 67% without compromising the cell capacity. This solution-based deep chemical prelithiation promises high-energy LICs based on transition metal-free, earth-abundant active materials to meet the practical demands of power-intensive applications.

A high-efficient stable surface-prelithiated Li1.2Ni0.13Co0.13Mn0.54O2 cathode enabled by sacrificial lithium nitrides for high-energy-density lithium-ion batteries

Lithium-rich cathode materials with superior practical specific capacity over 250 mAh g−1 are considered as one of the resolutions for high-energy-density lithium-ion batteries, while the intrinsic capacity loss caused by solid electrolyte interface (SEI) formation on the anode impedes the increase of energy density. To address this issue, we propose a composite cathode prelithiation strategy including a carbon-incorporated lithium phosphorus oxynitride (LiCPON) layer and a sacrificial Li3N (Sac. Li3N) layer, which can not only compensate for the capacity loss effectively and controllably with a high lithium utilization rate over 85% but also provide outstanding atmosphere stability with an 80.2% lithium utilization rate after exposed in dry air for 8 hours. The energy densities achieve 489.5 Wh kg−1 and 497.3 Wh kg−1 initially after cathode prelithiation in full cells paired with Si/C and SiOx/C anodes, corresponding to a 11.9% and 11.6% increase, respectively. The energy densities still remain 318.7 Wh kg−1 and 319.7 Wh kg−1 after 50 cycles with an increase of 13.7% and 11.7%, respectively. The cathode electrolyte interface (CEI) and SEI layers are mutually optimized and the electrolyte adsorption and degradation are suppressed after cathode prelithiation. Our work has demonstrated that such a composite cathode prelithiation strategy provides the possibility for large-scale industrial production, transportation, and conservation of prelithiated lithium-rich cathodes to achieve high-energy-density lithium-ion batteries.

Pre-lithiation strategy to design a high-performance zinc oxide anode for lithium-ion batteries.

Zinc oxide (ZnO) shows great potential as an anode material for advanced energy storage devices owing to its good structural stability and low cost. However, its inferior cycling capacity seriously restricts its practical application. In this work, a pre-lithiation strategy is adopted to construct pre-lithiated ZnO (Li-ZnO) via the facile solid-state reaction method. This well-designed Li-ZnO is polycrystalline, consisting of fine particles. XPS analysis and Raman results confirm the successful pre-lithiation strategy. The pre-lithiation strategy increases the electronic conductivity of Li-ZnO without further carbon coating and suppresses the volume expansion during the electrochemical reaction. As a result, 5 mol% Li-ZnO displays good reversible capacity with a specific capacity of 639 mA h g-1 after 200 cycles at 0.1 A g-1. After 1440 cycles at 1.0 A g-1, the capacity retention is 380 mA h g-1. The pseudocapacitance contribution can reach up to 72.5% at 1.0 mV s-1. Electrochemical kinetic analysis shows that this pre-lithiation strategy can accelerate the lithium-ion diffusion and charge transfer kinetics of the Li-ZnO anode and suppress the pulverization of the electrochemical reaction. This study demonstrates the necessity of developing new anode materials with good cycling stability via this pre-lithiation strategy.

Lithium sulfide: a promising prelithiation agent for high‐performance lithium‐ion batteries

AbstractLithium‐ion batteries are widely used in portable electronics and electric vehicles due to their high energy density, stable cycle life, and low self‐discharge. However, irreversible lithium loss during the formation of the solid electrolyte interface greatly impairs energy density and cyclability. To compensate for the lithium loss, introducing an external lithium source, that is, a prelithiation agent, is an effective strategy to solve the above problems. Compared with other prelithiation strategies, cathode prelithiation is more cost‐effective with simpler operation. Among various cathode prelithiation agents, we first systematically summarize the recent progress of Li2S‐based prelithiation agents, and then propose some novel strategies to tackle the current challenges. This review provides a comprehensive understanding of Li2S‐based prelithiation agents and new research directions in the future.

Core/Shell Cu-TiO2 Nanoparticles As Efficient Anode Material for Li-Ion Capacitors

Lithium-ion capacitor (LIC) belongs to a specific category of energy storage materials [1]. It is a combination of an electrode from a lithium-ion battery (LIB) with an electrode from an electrical double layer capacitor (EDLC). A usage of these two electrodes in one system results in formation of a hybrid energy device which can exhibit desired properties, such as: charge/discharge rapid capability, long cycle life and high energy density. However, the widescale usage of LICs is still limited due to the inherent low concentration of Li-ions in this system [2]. Typically, to improve it, an electrode needs to be pre-lithiated. There are many pre-lithiation methods that have been developed and implemented, but with varying level of success [3]. Therefore, the most optimal solution is to remove completely the need of pre-lithiation. In this work, we propose an approach which eliminates the requirement of pre-lithiation by designing a core-shell structure for the anodic active material. Herein, the shell is the material responsible for electrochemical activity and the core facilitates electronic conductivity.Titanium dioxide (α-TiO2), a well-researched anode material, was used as the shell, while copper (Cu), a highly conductive metal, was used as a core. Cu@TiO2 core-shell structures were synthesized by a wet-chemistry approach. The microscopic studies of chemical composition and morphology confirmed that the formation of TiO2 on the surface of copper was successful. Electrochemical measurements in the half cell of the electrode with Cu@TiO2 as the active material showed a specific capacity of around 156 mAh g-1. Next, the Cu@TiO2 anode was tested in a LIC against cathode with activated carbon as the active material. The resulting LIC showed showed high specific capacity and stable cycling behavior up to a 1000 cycles at 2.5 A g-1, with a coulombic efficiency of around 98%. Rate capability tests also showed relatively high stability of the anode material at low to high current rates.The results of this work open up potential avenues for further research focused on designing anode structures for LICs. The core-shell structure with Cu as the core and α-TiO2 as the shell has been demonstrated to enhance the stability of the capacitor and remove the need for pre-lithiation. The combination of low-cost and environmentally friendly materials for anode, and ease of LIC assembly, makes this a promising material for LICs.[1] Amatucci, G.G.; Badway, F.; du Pasquier, A.; Zheng, T. An Asymmetric Hybrid Nonaqueous Energy Storage Cell. J. Electrochem. Soc. 2001, 148, A930[2] Wang, H.; Zhu, C.; Chao, D.; Yan, Q.; Fan, H.J. Nonaqueous hybrid lithium-ion and sodium-ion capacitors. Adv. Mater. 2017, 29, 1702093[3] Holtstiege, F.; Bärmann, P.; Nölle, R.; Winter, M.; Placke, T. Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges. Batteries 2018, 4, 4

Spent-graphite anode from failed batteries: Regeneration and chemical prelithiation for sustainable fresh Li-ion batteries

Recycling of spent lithium-ion batteries require substantial attention for a sustainable future. Increasing deployment of batteries leads to large volume of failed batteries few years later depending on life time of the batteries. Recycling of graphite from the failed batteries has been mostly ignored. Graphite requirement of 1800 kt by 2030 is projected, which is approximately 260 % increase compared to present consumption. Present work unveils a solution to the increasing demand of battery-grade graphite anodes by a sustainable process. The combined practice of regeneration and prelithiation of spent-graphite (SG) is a viable solution for industrial scale processing. Regeneration process includes two steps, washing with N-Methyl-2-pyrrolidone and thermal processing. Regenerated SG has been tested for half-cell that delivered a poor initial Coulombic efficiency (ICE) of about 65 % only, which could affect the full-cell performance. To improve ICE, a chemical prelithiation strategy leading to higher ICE with a mean value of 103.5 % has been achieved. Also, reversible capacity of about 410 mAh/g at a specific current of 100 mA/g, good cycling stability and rate capability has been demonstrated. Further, the prelithiated SG anode coupled with LiMn2O4 cathode delivered an initial energy density of 370 Wh/kg in a lab-scale cell demonstrating its potential.