次世代リチウム電池をより安全・持続可能にする技術進展（WPI Researchers Pioneer Advances to Make Next-Generation Lithium Batteries Safer, More Sustainable, and Ready for Widespread Use）

2025-09-22 ウースター工科大学 (WPI)

＜関連情報＞

• https://www.wpi.edu/news/wpi-researchers-pioneer-advances-make-next-generation-lithium-batteries-safer-more-sustainable-and
• https://www.sciencedirect.com/science/article/abs/pii/S2542435125003174
• https://www.sciencedirect.com/science/article/abs/pii/S1369702125003931

使用済みリチウム金属アノードから高純度のLi 2 CO 3回収を可能にする自己駆動型アルドール縮合 Self-driven aldol condensation enabling high-purity Li2CO3 recovery from spent lithium metal anodes

Hao Zhou, Jaemin Kim, Jiahui Hou, Zifei Meng, Zeyi Yao, Zexin Wang, Yan Wang
Joule  Available online: 22 September 2025
DOI:https://doi.org/10.1016/j.joule.2025.102136

Graphical abstract

Highlights

• A practical strategy is proposed to recover highly reactive spent Li-metal anodes
• The reaction mechanism of commercial acetone with Li metal is clarified
• Recovered Li₂CO₃ meets battery-grade purity and matches commercial quality
• The proposed method demonstrates good scalability and economic viability

Context & scale

The pursuit of higher energy density is rapidly advancing the commercialization of lithium metal batteries, but their safe and efficient recycling remains an unmet challenge. Existing approaches are largely designed for primary lithium metal batteries and are ill-suited to address the high reactivity and dendrite-rich anodes of rechargeable systems. Here, we demonstrate a scalable and economically viable method using commercial acetone, where trace water gradually consumes lithium dendrites to reduce reactivity while simultaneously initiating a “self-driven” aldol condensation that drives safe lithium recovery. Beyond enabling sustainable development of rechargeable lithium metal batteries, this strategy also provides a framework for recycling other next-generation batteries that employ alkali-metal anodes with high reactivity.

Summary

Rechargeable lithium (Li)-metal batteries with high energy densities are approaching large-scale commercialization but face challenges in recycling due to the high reactivity of spent Li-metal anodes (S-LMAs). Here, we propose a recovery strategy using commercial acetone containing <1.00 wt % water. Sub-percent water first reacts with S-LMA to form LiOH, which consumes Li dendrites and mitigates safety risks. Then, LiOH catalyzes acetone aldol condensation to low-concentration diacetone alcohol (DAA, <5 mol %), which further reacts with S-LMA at acceptable rates and simultaneously drives the DAA production, thus achieving complete conversion of S-LMA. This approach yields high-purity Li₂CO₃ (99.79 wt %), surpassing the battery-grade standard (99.50 wt %). The recovered Li₂CO₃ enables the synthesis of LiNi_0.6Mn_0.2Co_0.2O₂ cathodes with electrochemical performance comparable to those from commercial Li₂CO₃. Combining safety, scalability, and economic viability, this method provides a practical route for recycling rechargeable Li-metal batteries and offers insights for extending to other alkali-metal-based batteries.

ハロゲン化物固体電解質用Li-inアノードへの安定界面のin-situ形成 In-situ formation of stable interface towards Li-in anode for halide solid-state electrolyte

Jinzhao Fu, Wenting Jin, Songge Yang  Jiahui Hou, Zifei Meng, Guangchen Liu, Zeyi Yao, Zexin Wang, Zhenzhen Yang, Yu Zhong, Yan Wang
Materials Today  Available online: 12 September 2025
DOI:https://doi.org/10.1016/j.mattod.2025.08.038

Abstract

Halide-based solid-state electrolytes (SSEs) are promising candidates for next-generation all-solid-state lithium batteries (ASSLBs) due to their high ionic conductivity and chemical stability. However, their poor interfacial compatibility with lithium metal anode and Li-In alloy significantly hinder practical application due to the requirement for a protective interlayer. In this study, a novel approach to overcome this limitation is presented by introducing iron (Fe) doping into Li₃InCl₆ (LIC), which enables direct and stable contact with lithium-indium (Li-In) metal without a protective interlayer. Thermodynamic and computational analyses identified Fe³⁺ as a suitable dopant based on its similar reduction potential to In³⁺ and structural compatibility within the halide lattice. The synthesized 10 at. % Fe-doped LIC exhibits high phase purity, retained ionic conductivity, and notably improved interfacial stability. Full-cell tests using Fe-LIC achieve over 300 cycles with 80 % capacity retention. At the same time, symmetric Li-In/ Fe-LIC/ Li-In cells sustain over 500 h of operation, representing the first reported long-term cycling of LIC-based ASSLB without a protective interlayer. This work establishes Fe doping as an effective strategy to stabilize halide SSEs of In system against Li-In alloy, thereby simplifying cell architecture and advancing the development of safer, high-performance halide-based solid-state electrolytes.