Off-Line Robust Constrained MPC for Linear Time-Varying Systems with Persistent Disturbances

An off-line robust constrained model predictive control (MPC) algorithm for linear time-varying (LTV) systems is developed. A novel feature is the fact that both model uncertainty and bounded additive disturbance are explicitly taken into account in the off-line formulation of MPC. In order to reduce the on-line computational burdens, a sequence of explicit control laws corresponding to a sequence of positively invariant sets is computed off-line. At each sampling time, the smallest positively invariant set containing the measured state is determined and the corresponding control law is implemented in the process. The proposed MPC algorithm can guarantee robust stability while ensuring the satisfaction of input and output constraints. The effectiveness of the proposed MPC algorithm is illustrated by two examples

Technological Applications of Honeycomb Monoliths Prepared via Extrusion and Coating of Structured Supports in Environmental Processes: A Review

Chulalongkorn University (Thailand

Enhanced cycling performance of rechargeable zinc–air flow batteries using potassium persulfate as electrolyte additive

Copyright © 2020 by the authors. Zinc–air batteries (ZABs) offer high specific energy and low-cost production. However, rechargeable ZABs suffer from a limited cycle life. This paper reports that potassium persulfate (KPS) additive in an alkaline electrolyte can effectively enhance the performance and electrochemical characteristics of rechargeable zinc–air flow batteries (ZAFBs). Introducing redox additives into electrolytes is an effective approach to promote battery performance. With the addition of 450 ppm KPS, remarkable improvement in anodic currents corresponding to zinc (Zn) dissolution and limited passivation of the Zn surface is observed, thus indicating its strong effect on the redox reaction of Zn. Besides, the addition of 450 ppm KPS reduces the corrosion rate of Zn, enhances surface reactions and decreases the solution resistance. However, excess KPS (900 and 1350 ppm) has a negative effect on rechargeable ZAFBs, which leads to a shorter cycle life and poor cyclability. The rechargeable ZAFB, using 450 ppm KPS, exhibits a highly stable charge/discharge voltage for 800 cycles. Overall, KPS demonstrates great promise for the enhancement of the charge/discharge performance of rechargeable ZABs.R.K. thanks Chulalongkorn Academic Advancement into its Second Century Project: C2F Postdoctoral Fellowship. Global Partnership Funding (B16F630071) and the Energy Storage Cluster, Chulalongkorn University are acknowledged. T.Y. thanks the finance support from Accelerating Social Implementation for SDGs Achievement (aXis) program of Japan Science and Technology Agency (JST)

Advances in characteristics improvement of polymeric membranes separators for zinc air batteries

Zinc air batteries ZABs are gaining popularity for a wide range of applications due to their high energy density, excellent safety, and environmental friendliness. A membrane separator is a critical component of ZABs, with substantial implications for battery performance and stability, particularly in the case of a battery in solid state format, which has captured increased attention in recent years. In this review, recent advances as well as insight into the architecture of polymeric membrane separators for ZABs including porous polymer separators PPSs , gel polymer electrolytes GPEs , solid polymer electrolytes SPEs and anion exchange membranes AEMs are discussed. The paper puts forward strategies to enhance stability, ionic conductivity, ionic selectivity, electrolyte storage capacity and mechanical properties for each type of polymeric membrane. In addition, the remaining major obstacles as well as the most potential avenues for future research are examined in detai

Phosphonated graphene oxide modified polyacrylamide hydrogel electrolytes for solid state zinc ion batteries

Compared to rigid batteries using liquid electrolytes, solid state batteries SSBs offer several advantages flexibility, prevention of leakage, suppression of dendritic formation and hydrogen evolution, as well as minimization of cathode active material dissolution. For the materialization of real life SSBs, gel polymer electrolytes GPEs are among promising candidates. However, development of GPEs with satisfying ionic conductivity and mechanical endurance is challenging. Herein, we report on the development of polyacrylamide PAM phosphonated graphene oxide PGO nanocomposite hydrogel electrolytes for zinc ion batteries; PGO acts as the filler through in situ polymerization of acrylamide in an aqueous suspension of PGO. The synthesized PAM PGO hydrogel exhibits high ionic conductivity of 31.0 mS cm at 30 C compared to that of PAM 13.8 mS cm and PAM GO 20.8 mS cm . The higher ionic conductivity of PAM PGO can be attributed to its higher hydrophilicity and electrolyte storage capacity along with its lower activation energy for ionic conduction 7.2 KJ mol K in comparison with that of PAM 10.1 KJ mol K and PAM GO 10.2 KJ mol K . The interaction between water against PAM, PAM GO and PAM PGO is investigated via density functional theory DFT . The MnO2 based zinc ion battery assembled using PAM PGO as electrolyte shows high initial capacity of 240 mAh g, losing only 4 and 15 of its capacity after 100 and 145 cycles, respectively. Results demonstrate promising potential of PAM PGO as a solid state electrolyte for flexible battery application