Promises and Challenges of the Practical Implementation of Prelithiation in Lithium‐Ion Batteries

Abstract

graphite-based anodes, active lithium from the lithium-containing oxide or phosphate cathode is consumed due to the side reactions during the formation of solid electrolyte interface (SEI) on the anode surface, accompanied by the decomposition of liquid electrolyte. This leads to Coulombic efficiency values lower than 100% in the very initial charge/discharge cycles (e.g., 90%-95% for the first cycle), which appreciably reduces the energy density of LIBs. [10][11][12][13] For the next-generation highenergy-density LIBs, high-capacity anodes (e.g., Si, Sn, and P with alloy reaction mechanism) undergo much more serious side reactions and show much more initial lithium loss (e.g., >15%) than the graphitebased anodes. Moreover, the side reactions of these high-capacity anodes continue to take place for several cycles, sometimes even tens of cycles, before the stabilization of Coulombic efficiency to over 99.9%, due to the large volume change of these materials (e.g., ≈420% for Si, ≈260% for Sn, and ≈300% for P) from lithium-free state to full lithiation state, which leads to large amount of accumulated lithium loss. [14,15] Consequently, the usable lithium-ion capacity and overall energy density of LIBs using these high-capacity anode materials would be significantly decreased.Prelithiation has been widely investigated as a promising strategy to resolve this lithium loss issue and increase the energy density of LIBs. With the specific purpose of compensating for the initial lithium loss in LIBs, prelithiation is conceptually independent from the pretreatment of battery materials or electrodes, and it can be simply regarded as providing additional active lithium using specific prelithiation reagents/ materials or processing to LIBs prior to battery cell cycling. To increase active lithium inside the entire LIBs, prelithiation can be performed on different battery components, cathodes, or anodes, and also at different levels, materials, or electrodes, depending on the prelithiation approaches. Till now, various prelithiation methods have been developed, including electrochemical prelithiation at the electrode level, [16][17][18][19] chemical prelithiation at the materials or electrode level, [20][21][22] prelithiation additives for cathodes and anodes, [8,[23][24][25][26][27] and direct contact/short circuit between a negative electrode and a lithium metal foil. [28][29][30][31] These prelithiation methods with various mechanisms show different prelithiation efficiency or capability in increasing the energy density of LIBs and other effects, and Lithium-ion batteries (LIBs) have changed lives since their invention in the early 1990s. Further improvement of their energy density is highly desirable to meet the increasing demands of energy storage applications. Active lithium loss in the initial charge process appreciably reduces the capacity and energy density of LIBs due to the formation of a solid electrolyte interface (SEI) on the anode surface, especially for Si based anodes in high-energy-density batteries. To solve...

In Situ Electrochemical Regeneration of Degraded LiFePO4 Electrode with Functionalized Prelithiation Separator

“…Herein, inspired by the prethiation methods in LIBs, [33,34] we propose a regeneration strategy for spent LFP. Electrochemical reproducibility of the spent LFP scraps is confirmed through detailed characterization and analysis, and then a novel functionalized prelithiation separator (FPS) which stores releasable active Li + is applied.…”

Practical Prelithiation of 4.5 V LiCoO2||Graphite Batteries by a Passivated Lithium‐Carbon Composite

“…[4] Therefore, it is compelling to compensate for this irreversible Li consumption.An intuitive strategy to address this issue is prelithiation, i.e., introducing additional active lithium into the battery before cell cycling to compensate for the active lithium loss during SEI formation. [5] In recent years, some prelithiation strategies have been developed, including electrochemical prelithiation of the electrodes, [6] chemical prelithiation of electrode active materials or electrodes, [2,7] and adding sacrificial prelithiation reagent to electrode slurry. [3][4]8] Amongst these approaches, incorporating prelithiation additives into the electrode slurry is a facile strategy that does not involve extra treatments in battery manufacturing, thus this method has been widely investigated.…”

Robust Solid Electrolyte Interphases in Localized High Concentration Electrolytes Boosting Black Phosphorus Anode for Potassium-Ion Batteries

“…This value is lower than the theoretical prediction due to the K ion consumption in the SEI formation, which may be resolved through pre-potassiation techniques, similar to those adopted in lithium-ion and sodium-ion batteries. 65,66 We also couple the BP/G with a high-voltage KVPO 4 F cathode (Figure S20), demonstrating again the compatibility of the as-prepared anode and electrolyte. Overall, these results indicate that the LHCE is fully compatible with the cathode.…”