Actualizing a High-Energy Bipolar-Stacked Solid-State Battery with Low-Cost Mechanically Robust Nylon Mesh-Reinforced Composite Polymer Electrolyte Membranes

Abstract

To meet the rapidly growing and diversified demand for energy storage, advanced rechargeable batteries with high-performance materials and efficient battery configuration are widely being exploited and developed. Bipolar-stacked electrode coupling with solid-state electrolytes enables achieving batteries with high output voltage, high energy density, and simple components. Here, a polymer electrolyte membrane is designed with polyethylene oxide containing bis(trifluoromethanesulfonyl)imide as the electrolyte, succinonitrile as the plasticizer, and nylon mesh as a reinforcement for the bipolar-stacked battery. The asprepared nylon mesh-reinforced polymer electrolyte membrane shows advantageous features, that is, excellent ionic conductivity (3.38 × 10 −4 S cm −1 ) at room temperature, low interface impedance, and good tolerance against the expansion caused by the plating/stripping of the Li anode and the electrode upon cycling. When used as a polymer electrolyte membrane in the bipolar-stacked battery, the LiFePO 4 (LFP)−Li 4 Ti 5 O 12 (LTO) cell with three cells connected in series delivers a higher discharge voltage (5.4 V) and a volumetric energy density (0.328 mW h cm −3 ), nearly 3 times as much as that of the LFP−LTO battery. In addition, LiFePO 4 −Li pouch cells using the polymer electrolyte membrane can sustain the abuse tests including bending, cutting, and nail penetration well. These results pave a new avenue to develop highperformance polymer electrolyte membranes and allow for the design of high-voltage and volumetric energy density bipolar-stacked batteries.

Challenges and Solutions of Solid‐State Electrolyte Film for Large‐Scale Applications

“…The assembled Li|LAGP@bacterial cellulose‐PEO|LiFePO 4 battery has a specific capacity of up to 168.2 mAh g −1 at 1C and 60 °C and a capacity retention of 90.4% after 200 cycles. Similar work has also been done to prepare a 158.7um [ 194 ] thick CSE with nylon mesh as the supporting matrix.…”

“…Although the solution casting method has been widely used for the large‐scale preparation of polymer‐based SSEs due to the simplicity and maturity of the process, the ability to incorporate a variety of additives as needed, the ease of preparing composite solid electrolytes with oxide/sulfide SSEs, and the ease of infiltration into porous and skeletal materials, the method has been prominent in CPEs in particular due to the integration of the advantages of each of the SPEs and inorganic SSEs. [ 170–172 ] There are five main structural designs studied, namely free‐standing SSE, [ 159–169 ] skeleton supporting SSE, [ 173–194 ] SSE with low tortuosity, [ 195–198 ] electrode‐supporting SSE [ 199–201 ] and in situ polymerization. [ 182,202–208 ] However, it is worth noting that the solution casting method is mainly based on SPE for the preparation and design of CSE, and the introduction of SPE will force the ASSB to operate at high temperatures, in addition, the complete filling of pores in the skeleton is a challenge, too little will lead to the limitation of the performance of composite solid electrolyte, and too much will affect the energy density of the battery.…”

Understanding Lithium Dendrite Suppression by Hybrid Composite Separators: Indentation Measurements Informed by Operando X-ray Computed Tomography

“…For example, high-modulus materials such as oxide or sulfide inorganic solid-state electrolytes often show lithium plating (formation of lithium filaments) through grain boundaries and cracks within the material . Sufficiently robust mechanical properties, including Young’s modulus, are often cited as a performance metric of polymeric electrolytes, separators, and coatings; however, elastic properties often fail to correlate with better battery performance across several studies, as shown in Figure . − An alternative performance metric used here to compare several organic materials within lithium metal/lithium iron phosphate cells combines the capacity retention, C-rate, and number of cycles reported in these works, and is defined by eq performance 0.25em metric = capacity 0.25em retention × normalC − rate × number 0.25em of 0.25em cycles false) …”