Flexible aqueous lithium-ion batteries with ultrahigh areal capacity and long cycle life

• Published in: Materials today energy 2021-03, Vol.19, p.100570, Article 100570
• Main Authors: Zhou, Y., Wang, Z., Lu, Y.-C.
• Format: Article
• Language: English
• Subjects: Batteries; Graphite felt; High mass loading; Three-dimensional flexible electrodes
• ISSN: 2468-6069; 2468-6069
• DOI: 10.1016/j.mtener.2020.100570

Practical application of flexible batteries have been hindered by low areal capacity, low stability, and safety concerns. This work reports a facile and scalable infiltration method to fabricate free-standing three-dimensional (3D) flexible electrodes using LiTi2(PO4)3 (LTP) and LiMn2O4 (LMO) as examples for aqueous Li-ion batteries. Benefiting from the unique 3D electrode architecture with fast electron and ion transport, flexible LTP-LMO pouch cells deliver an ultrahigh areal capacity (e.g., 3–23 mAh cm−2, LTP loading = 24–200 mg cm−2), high rate capability, and stable cycling stability (e.g., 93% and 72% capacity retention after 500 and 3000 cycles, respectively, at 14–15 mA cm−2). High mechanical and electrochemical stability of the cell is demonstrated with a high capacity retention of 96% after 1000 dynamic bending cycles. Pouch cells with a high capacity (0.53 Ah for 4 × 6 cm2 cell) and high voltage (3 V/9 V) are demonstrated. This work offers a low-cost and effective strategy to fabricate high areal capacity electrodes with stable electrochemical performance, high mechanical strength, and excellent flexibility. [Display omitted] •A facile infiltration method was developed to fabricate flexible electrodes.•Flexible aqueous lithium-ion batteries achieved an ultrahigh areal capacity of 23 mAh cm−2.•High mechanical and electrochemical stability of the battery was demonstrated.