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A flame-retardant solid polymer electrolyte (FR-SPE) membrane was successfully designed through UV-curing flame-retardant polyurethane acrylate (PUA) oligomers, succinonitrile, aluminum oxide (Al2O3), and lithium salt. The flame retardant PUA is formed by grafting reactive flame-retardant 9,10-dihydro-9-oxa-10-phenanthrene-10-oxide (DOPO) on the main chain of the oligomer. The cross-linked PUA ensures excellent mechanical properties and high flame retardancy of FR-SPE. Moreover, the flame retardancy of the FR-SPE can reach the V-0 level of the UL-94 test when the grafting rate of DOPO on PUA reached 39%, and the obtained FR-SPE achieves a high ionic conductivity of 2.66 × 10–4 S cm–1 at room temperature, a wide electrochemical stability window of 5 V, and a high lithium-ion transfer number of 0.55. Moreover, FR-SPE shows a stable lithium plating/stripping response for over 600 h under a constant current density of 0.1 mA cm–2. Meanwhile, the cell of LiFePO4/FR-SPE/Li4Ti5O12 has excellent cycling stability (144.6 mA h g–1 at 0.2 C after 100 cycles) and rate capability (107.4 mA h g–1 at 5 C). In addition, the electrolyte has no adverse effect on the cycle performance of batteries with graphite electrodes. Thus, such cross-linked flame-retardant SPEs are argued to provide an effective method for more broadly enhancing lithium battery safety and performance.

In aerospace, the design principles have transformed from the pursuit of performance to a balance among performance, costs, reliability and other aspects, and how to meet the system performance requirements under the premise of minimizing costs has become a serious problem. In this paper, the relationships between the constellation availability and the satellite reliability were modeled considering the replacement mode of the back-up satellite. A case study was presented to show the effects of the satellite reliability on constellation availability.

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