Individuals with severe neuromuscular impairments face many challenges in communication and manipulation of the environment. Brain-computer interfaces (BCIs) show promise in presenting real-world applications that can provide such individuals with the means to interact with the world using only brain waves. Although there has been a growing body of research in recent years, much relates only to technology, and not to technology in use—i.e., real-world assistive technology employed by users. This review examined the literature to highlight studies that implicate the human factors and ergonomics (HFE) of P300-based BCIs. We assessed 21 studies on three topics to speak directly to improving the HFE of these systems: (1) alternative signal evocation methods within the oddball paradigm; (2) environmental interventions to improve user performance and satisfaction within the constraints of current BCI systems; and (3) measures and methods of measuring user acceptance. We found that HFE is central to the performance of P300-based BCI systems, although researchers do not often make explicit this connection. Incorporation of measures of user acceptance and rigorous usability evaluations, increased engagement of disabled users as test participants, and greater realism in testing will help progress the advancement of P300-based BCI systems in assistive applications.

Composite polymer electrolytes (CPEs) incorporate the advantages of solid polymer electrolytes (SPEs) and inorganic solid electrolytes (ISEs), which have shown huge potential in the application of safe lithium-metal batteries (LMBs). Effectively avoiding the agglomeration of inorganic fillers in the polymer matrix during the organic–inorganic mixing process is very important for the properties of the composite electrolyte. Herein, a partial cross-linked PEO-based CPE was prepared by porous vinyl-functionalized silicon (p-V-SiO2) nanoparticles as fillers and poly (ethylene glycol diacrylate) (PEGDA) as cross-linkers. By combining the mechanical rigidity of ceramic fillers and the flexibility of PEO, the as-made electrolyte membranes had excellent mechanical properties. The big special surface area and pore volume of nanoparticles inhibited PEO recrystallization and promoted the dissolution of lithium salt. Chemical bonding improved the interfacial compatibility between organic and inorganic materials and facilitated the homogenization of lithium-ion flow. As a result, the symmetric Li|CPE|Li cells could operate stably over 450 h without a short circuit. All solid Li|LiFePO4 batteries were constructed with this composite electrolyte and showed excellent rate and cycling performances. The first discharge-specific capacity of the assembled battery was 155.1 mA h g−1, and the capacity retention was 91% after operating for 300 cycles at 0.5 C. These results demonstrated that the chemical grafting of porous inorganic materials and cross-linking polymerization can greatly improve the properties of CPEs.

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The use of gel polymer electrolytes (GPEs) is recognized as a promising strategy to improve the safety characteristics of current lithium-ion batteries (LIBs) due to the incorporation of polymer matrix and immobilization of the liquid phase. To achieve high performance and efficient Li+ transport in GPEs, the selection of polymer is critically important. Herein, a single-ion-conducting GPE with a high lithium-ion transference number is proposed with lithiated Nafion (Li-Nafion) and polyacrylonitrile (PAN) polymers. We found that the interactions between electron-withdrawing CN groups Li+ facilitate fast Li+ transport and reduce the Li+ migration barrier of Li+ on the −SO3 – groups. As a consequence, the designed GPE shows a high lithium-ion transference number of 0.93, an admirable ionic conductivity of 1.93 × 10–4 S cm–1, and a wide electrochemical stability window up to 5.0 V at 30 °C. Further validation of the Li|LiFePO4 cell shows a decent cycling performance with an initial discharge specific capacity of 126.1 mAh g–1 and a high capacity retention of 90.1% after 200 charge/discharge cycles at 1C. This study provides a strategy of Li-Nafion and a “decoupling” polymer to enhance the GPE performance and its applications on LIBs.