Improved Interface Stability and Room-Temperature Performance of Solid-State Lithium Batteries by Integrating Cathode/Electrolyte and Graphite Coating

Advances in Inorganic Solid-State Electrolyte/Li Interface

The increasing demand for high-energy-density and high-safety energy storage devices has sparked a growing interest in all-solid-state lithium metal batteries (ASSLMBs). A high-quality inorganic solid-state electrolyte (ISE) is a fundamental requirement for ASSLMBs, and an effective ISE/Li interface is a key factor in attaining high-performance ASSLMBs. In this Concept, we initially summarize the challenges encountered by ISE/Li interfaces and delineate four commonly employed strategies for modifying the ISE/Li interface. Then, we explore the merits and drawbacks of coatings utilized as ISE/Li interfacial phases. We also delve into the commonly employed thermal bonding and innovative cold bonding methods utilized for in situ interface preparation. Lastly, we spotlight future directions for enhancing the functionality of ISE/Li interfaces and achieving high-performance ASSLMBs.

Conversion of Natural Biowaste into Energy Storage Materials and Estimation of Discharge Capacity through Transfer Learning in Li-Ion Batteries

To simultaneously reduce the cost of environmental treatment of discarded food waste and the cost of energy storage materials, research on biowaste conversion into energy materials is ongoing. This work employs a solid-state thermally assisted synthesis method, transforming natural eggshell membranes (NEM) into nitrogen-doped carbon. The resulting NEM-coated LFP (NEM@LFP) exhibits enhanced electrical and ionic conductivity that can promote the mobility of electrons and Li-ions on the surface of LFP. To identify the optimal synthesis temperature, the synthesis temperature is set to 600, 700, and 800 °C. The NEM@LFP synthesized at 700 °C (NEM 700@LFP) contains the most pyrrolic nitrogen and has the highest ionic and electrical conductivity. When compared to bare LFP, the specific discharge capacity of the material is increased by approximately 16.6% at a current rate of 0.1 C for 50 cycles. In addition, we introduce innovative data-driven experiments to observe trends and estimate the discharge capacity under various temperatures and cycles. These data-driven results corroborate and support our experimental analysis, highlighting the accuracy of our approach. Our work not only contributes to reducing environmental waste but also advances the development of efficient and eco-friendly energy storage materials.

Revealing Surfactant Effect of Trifluoromethylbenzene in Medium-Concentrated PC Electrolyte for Advanced Lithium-Ion Batteries

Despite wide-temperature tolerance and high-voltage compatibility, employing propylene carbonate (PC) as electrolyte in lithium-ion batteries (LIBs) is hampered by solvent co-intercalation and graphite exfoliation due to incompetent solvent-derived solid electrolyte interphase (SEI). Herein, trifluoromethylbenzene (PhCF₃ ), featuring both specific adsorption and anion attraction, is utilized to regulate the interfacial behaviors and construct anion-induced SEI at low Li salts' concentration (<1 m). The adsorbed PhCF₃ , showing surfactant effect on graphite surface, induces preferential accumulation and facilitated decomposition of bis(fluorosulfonyl)imide anions (FSI^- ) based on the adsorption-attraction-reduction mechanism. As a result, PhCF₃ successfully ameliorates graphite exfoliation-induced cell failure in PC-based electrolyte and enables the practical operation of NCM613/graphite pouch cell with high reversibility at 4.35 V (96% capacity retention over 300 cycles at 0.5 C). This work constructs stable anion-derived SEI at low concentration of Li salt by regulating anions-co-solvents interaction and electrode/electrolyte interfacial chemistries.

In Situ Formed Li-Ag Alloy Interface Enables Li10GeP2S12-Based All-Solid-State Lithium Batteries

All-solid-state lithium-metal batteries (ASSLMBs) have received great interest due to their high potential to display both high energy density and safety performance. However, the poor compatibility at the Li/solid electrolyte (SE) interface and penetration of lithium dendrites during cycling strongly impede their successful commercialization. Herein, a thin Ag layer was introduced between Li and Li₁₀GeP₂S₁₂ for the in situ formation of a Li-Ag alloy interface, thus tuning the interfacial chemistry and lithium deposition/dissolution behavior. Superior electrochemical properties and improved interfacial stability were achieved by optimizing the Ag thicknesses. The assembled symmetric cell with Li@Ag 1 μm showed a steady voltage evolution up to 1000 h with an areal capacity of 1 mAh cm^-2. Moreover, a high reversible capacity of 106.5 mAh g^-1 was achieved in an all-solid-state cell after 100 cycles, demonstrating the validity of the Ag layer. This work highlights the importance of the Li/SE interface re-engineering and provides a new strategy for improving the cycle life of ASSLMBs.

Artificial Cathode-Electrolyte Interphase towards High-Performance Lithium-ion Batteries: A Case Study of β-AgVO3

Silver vanadates (SVOs) have been widely investigated as cathode materials for high-performance lithium-ion batteries (LIBs). However, similar to most vanadium-based materials, SVOs suffer from structural collapse/amorphization and vanadium dissolution from the electrode into the electrolyte during the Li insertion and extraction process, causing poor electrochemical performance in LIBs. We employ ultrathin Al₂O₃ coatings to modify β-AgVO₃ (as a typical example of SVOs) by an atomic layer deposition (ALD) technique. The galvanostatic charge-discharge test reveals that ALD Al₂O₃ coatings with different thicknesses greatly affected the cycling performance. Especially, the β-AgVO₃ electrode with ~10 nm Al₂O₃ coating (100 ALD cycles) exhibits a high specific capacity of 271 mAh g⁻¹, and capacity retention is 31%, much higher than the uncoated one of 10% after 100 cycles. The Coulombic efficiency is improved from 89.8% for the pristine β-AgVO₃ to 98.2% for Al₂O₃-coated one. Postcycling analysis by cyclic voltammetry (CV), cyclic voltammetry (EIS), and scanning electron microscopy (SEM) disclose that 10-nm Al₂O₃ coating greatly reduces cathode-electrolyte interphase (CEI) resistance and the charge transfer resistance in the β-AgVO₃ electrode. Al₂O₃ coating by the ALD method is a promising technique to construct artificial CEI and stabilize the structure of SVOs, providing new insights for vanadium-based electrodes and their energy storage devices.