Taming Active Material-Solid Electrolyte Interfaces with Organic Cathode for All-Solid-State Batteries

Abstract

Forming compatible interfaces between cathode active materials and solid electrolytes is important for high-performance all-solid-state batteries. The organic cathode demonstrated here is (electro)chemically and mechanically compatible with a sulfide electrolyte. Its moderate redox potential enables the reversible formation of a resistive active material-electrolyte interface. It also maintains intimate contact with the electrolyte during cycling because of favorable mechanical properties. These features have contributed to the record cycling stability for all-solid-state sodium batteries.

4 V room-temperature all-solid-state sodium battery enabled by a passivating cathode/hydroborate solid electrolyte interface

“…Specific energy in W h kg cathode À1 is exhibited as a product of specific discharge capacity and average discharge cell voltage, as recently proposed to enable performance comparison of all-solid-state batteries between different studies and cell chemistries. 2 Each color symbolizes the SEs used: oxides/polymers (blue), [66][67][68][69] sulfides (green), 21,23,[70][71][72] and hydroborates (orange and red). 41 Fig.…”

“…6 Comparison of state-of-the-art all-solid-state sodium and lithium battery performance. Specific discharge capacity, average discharge cell voltage, and operating voltage range are plotted for all-solid-state cells exhibiting 480% capacity retention for Z100 cycles, using insertion-type cathode active materials and SEs based on oxides/polymers (blue), [66][67][68][69] sulfides (green), 21,23,[70][71][72] and hydroborates (orange and red). 41 Each specific discharge capacity, normalized by the cathode composite weight in sodiated or lithiated states, 2 was measured at C/10, except for NCM60|Li, NCM75|Li, and NaFePO 4 |hard carbon at C/5, and for Na 4 PTO|Na-Sn at C/7.4 (= C/10 for PTO).…”

Two‐Dimensional (2D) Covalent Organic Framework as Efficient Cathode for Binder‐free Lithium‐Ion Battery

“…The Young's modulus of PTO, which is two orders of magnitude smaller than many metal‐oxide‐based cathodes (100–200 GPa), can effectively reduce the mechanical stress during cell cycling and prevent the loss of interparticle mechanical contact with the electrolyte. The soft mechanical properties of PTO compounds will be advantageous for the fabrication of flexible or stretchable battery electrodes . Secondly, the rigid skeleton connected by B 3 O 3 moieties facilitates the stabilization of the porous structure and allows the quick diffusion of lithium ions.…”

Anisotropically Electrochemical–Mechanical Evolution in Solid‐State Batteries and Interfacial Tailored Strategy

“…Here, in situ EIS of the first two cycles were performed to gain a detailed understanding of the interfacial resistance mechanism in solid‐state batteries (Supporting Information, Figures S10, S11). The initial discharge cycle is shown in Figure A and the evolution of the impedance spectra at the different DOD are illustrated in Figure B . To improve understanding the evolving interfacial resistance mechanism in solid‐state battery electrode, a series of solid‐state batteries at different discharging states were dissembled and the morphologies of FeS 2 composite electrodes were investigated with SEM (Figure C).…”

“…Thei nitial discharge cycle is shown in Figure 5A and the evolution of the impedance spectra at the different DOD are illustrated in Figure 5B. [23] To improve understanding the evolving interfacial resistance mechanism in solid-state battery electrode,aseries of solid-state batteries Figure 4. 2D cross-section mapping and heterogeneous phase conversion.…”