Computation-Accelerated Design of Materials and Interfaces for All-Solid-State Lithium-Ion Batteries

Abstract

The all-solid-state lithium-ion battery is a promising next-generation battery technology. However, the realization of all-solid-state batteries is impeded by limited understanding of solid electrolyte materials and solid electrolyte-electrode interfaces. In this review, we present an overview of recently developed computation techniques and their applications in understanding and advancing materials and interfaces in all-solid-state batteries. We review the role of ab initio molecular dynamics simulations in studying fast ion conductors and discuss the capabilities of thermodynamic calculations powered by materials databases for identifying the chemical and electrochemical stability of solid electrolyte materials and solid electrolyte-electrode interfaces. We highlight the computational studies in the design and discovery of new solid electrolyte materials and outline design guidelines for solid electrolytes and their interfaces. We conclude with discussion of future directions in computation techniques, materials development, and interface engineering for all-solid-state lithium-ion batteries.

Lithium Chlorides and Bromides as Promising Solid‐State Chemistries for Fast Ion Conductors with Good Electrochemical Stability

“…Sulfide‐based solid‐state Li‐ion conductors such as Li 10 GeP 2 S 12 (LGPS) and Li 7 P 3 S 11 (LPS) show good ionic conductivity but narrow electrochemical windows and poor stability with electrodes, whereas oxide solid‐state Li‐ion conductors show significantly wider electrochemical windows but lower ionic conductivity . These general trends in the electrochemical stability of oxides and sulfides have been confirmed by high‐throughput calculations on a large number of materials . According to the design principles for superionic conductors (SICs) established by computational studies in sulfide SICs such as LGPS and LPS, Li ions migrate among face‐sharing tetrahedral sites in a body‐centered cubic (bcc) S‐anion lattice.…”

“…ASBs solve the safety issue caused by the flammability of organic liquid electrolyte and potentially provide higher energy density with Li metal anode and high‐voltage cathode materials . However, it has been a great challenge to develop solid‐state Li‐ion conductors with high Li + conductivity at room temperature comparable to that of liquid electrolytes and with good electrochemical stability for Li‐ion batteries with a voltage of >4 V. Current research efforts on solid‐state Li‐ion conductors focus mostly on oxides and sulfides . Unfortunately, oxide and sulfide chemistries have an undesirable trade‐off between ionic conductivity and stability.…”

“…In our AIMD simulations on the structures with Y‐on‐Li anti‐sites (Supporting Information, Figure S11, Table S2), the Li ionic conductivity at 300 K decreases by about an order of magnitude to 1.4–1.8 mS/cm (with a lower error bound of 0.3–0.4 mS/cm), and the activation energy increases to 0.31±0.03 eV, which are in better agreement with the experimental values and support our proposed mechanism of channel‐blocking defects. In addition, other effects such as impurity phases, grain boundaries, different microstructures, and local variations in composition resulting from different synthesis and processing conditions, may explain the discrepancy between experiments and computation …”

“…Besides LYC and LYB, we found these close‐packed hcp and fcc frameworks based on Cl and Br anion chemistry in general provide good ionic conductivity regardless of the cation. Our first principles calculations predicted several isomorph structures substituting Y 3+ in LYC and LYB with other 3 + cations, such as Li 3 MX 6 (M=Dy, Gd, Ho, La, Nd, Sc, Sm, Tb, Tm; X=Cl, Br), also have a good phase stability as measured by energy above the convex hull (Δ E hull ) (Supporting Information, Table S3) . We selected Ho and Sc substituted compounds, which showed good phase stability with Δ E hull <30 meV/atom, to further study their Li‐ion diffusion (Supporting Information, Figure S10).…”

Shaping the Contact between Li Metal Anode and Solid‐State Electrolytes

“…[ 18 ] Moreover, a nonflammable SSE would suppress side reactions, leading to safe operation of SSBs with high coulombic efficiency. [ 19–21 ] In addition, unwanted “cross‐talk” of the electrode is prohibited since only Li ions can transfer as charge carriers in SSE, which is possible to solve the problems of dissolution and shuttle effect for organic or sulfur electrodes. [ 22–25 ]…”