High-throughput Li plating quantification for fast-charging battery design

Abstract

Fast charging of most commercial lithium-ion batteries is limited due to fear of lithium plating on the graphite anode, which is difficult to detect and poses significant safety risk. Here we demonstrate the power of simple, accessible, and high-throughput cycling techniques to quantify irreversible Li plating spanning data from over 200 cells. We first observe the effects of energy density, charge rate, temperature, and State-of-Charge (SOC) on lithium plating, use the results to refine mature physicsbased electrochemical models, and provide an interpretable empirical equation for predicting the plating onset SOC. We then explore the reversibility of lithium plating for varied deposition rates, amounts, and electrolyte compositions, applying our understanding towards development of electrolytes that reduce irreversible Li formation. Finally, we provide the first quantitative comparison of lithium plating in the experimentally convenient Graphite|Li cell configuration compared with commercially relevant Graphite|LiNi0.5Mn0.3Co0.2O2 (NMC). The hypotheses and abundant data herein were generated primarily with equipment universal to the battery researcher, encouraging further development of innovative testing methods and data processing that enable rapid battery IntroductionThe urgent need to combat climate change has sparked extreme growth in demand for lithium-ion batteries (LIB). Rapid innovation in battery materials and cell design is critical to meet this demand for diverse applications from electronics to vehicles and utility-scale energy storage. Composite graphite electrodes remain a universal component of the LIB and are expected to dominate anode market share through 2030 despite the introduction of silicon and lithium-based materials 1 . The design space for graphite electrodes is immense, with parameters such as the loading, porosity, particle size, binder composition, and electrolyte being carefully selected to meet requirements for lifetime, operating temperature, charge time, and manufacturing. Regardless of design and application, the lithium plating reaction on graphite is a performance and safety concern due to the formation of noncyclable 'dead' lithium metal and salts. While recent studies have focused on Li plating during fast charging, the phenomenon is also pertinent to other operating extremes such as low temperature 2 , overcharge 3 , or system malfunction 4 . Electrochemical (EChem) modeling is an important tool for understanding design tradeoffs that improve graphite performance while avoiding plating. Over decades, Newman-based models that relate cell current density, voltage, temperature, and material properties to graphite intercalation have been enhanced to also estimate lithium plating. [5][6][7][8][9][10] This has led to initial insight into the effect of charge rate, electrode loading, and temperature on lithium plating onset/amount, but simulations rely on debated parameters such as the plating exchange current density or reversibility and are frequently not verified with direct ex...

Pattern Investigation and Quantitative Analysis of Lithium Plating under Subzero Operation of Lithium-Ion Batteries

“…However, some Li plating shows poor electrical contact with the anode such as Li plating near the separator. It will be isolated gradually during the discharging process, and dead Li is formed. , This part of Li plating cannot be oxidized into Li + to intercalate in the cathode, resulting in capacity loss and internal resistance increase, which is called irreversible plated Li. − Assuming that the capacity consumed by the SEI film at low temperatures is negligible, the irreversible Li capacity Q irr can be expressed as the difference between the charging capacity Q ch and the discharging capacity Q dc per cycle, as shown in Figure a. ,, The variation in Q irr with cycle number is shown in Figure d–f. The Q irr of the batteries cycled at 0 °C is much less than 0.01 mAh and follows the rule of 0.5C > 0.2C > 0.1C.…”

“…45−47 Assuming that the capacity consumed by the SEI film at low temperatures is negligible, the irreversible Li capacity Q irr can be expressed as the difference between the charging capacity Q ch and the discharging capacity Q dc per cycle, as shown in Figure 4a. 21,22,48 The variation in Q irr with cycle number is shown in Figure 4d−f. The Q irr of the batteries cycled at 0 °C is much less than 0.01 mAh and follows the rule of 0.5C > 0.2C > 0.1C.…”

Interfacial Electrochemical Media‐Engineered Tunable Vanadium Zinc Hydrate Oxygen Defect for Enhancing the Redox Reaction of Zinc‐Ion Hybrid Supercapacitors

“…[1] Among various energy storage strategies, lithium-ion batteries (LIBs) technology is mature and has attracted tremendous attention owing to the high energy density and long-term stability of LIBs, which enable their application in daily life devices, such as smart phones and electric vehicles. [2,3] However, there are critical problems associated with the implementation of EESSs in daily devices. For example, conventional LIBs are susceptible to explosion hazard and requires a high fabrication cost owing to the use of a flammable electrolyte, expensive cathode materials, and complex manufacturing processes.…”

Ant-Nest-like Lithiophilic Host for Long-Life Lithium Metal Anodes

“…Next-generation lithium batteries with high energy/power densities have been in urgent demand for the fast development of electric vehicles, portable electronic products, grid storage, etc. Lithium metal anodes (LMAs) are considered a better alternative to graphite electrodes because of their extremely high theoretical specific capacity (3860 mA h g –1 ) and lowest electrochemical potential (−3.04 V). − However, the high reactivity of Li with organic electrolytes will form an unstable solid electrolyte interface (SEI), and the infinite volume change due to the “host-free” nature of metallic Li will cause instability in the SEI layer. − The repeated breaking and reforming of the SEI will lead to uneven Li deposition, dendritic growth, and massive dead Li formation during repeated cycles, which might cause severe safety problems, and thus, effective strengthening of the SEI is required. − Moreover, the use of a large excessive amount of Li (typically ∼15–150 oversize compared to the cathode capacity) cannot be avoided by most Li metal battery configurations, and the huge volume change will cause the volume expansion of LMAs, which is not preferred in the industrial scaling-up. − Therefore, the stabilization of the spatial LMA structure, the effective guidance toward even Li deposition, and nonexcessive Li adoption are the keys for LMA innovation.…”