The emergence of organic nitrogen-oxide (NO) radical polymers has brought hope in the pursuit of high performance lithium-ion batteries (LIBs). However, the unstable conductivity has always caused the NO polymer electrodes to have inferior electrochemical performance. Herein, we constructed a new and remarkably conductive polynitroxide-grafted-graphene (NO-g-rGO) cathode that is similar to organic polymer cathodes with a high concentration of nitroxide radicals. Elevated levels of NO on the surface of reduced graphene oxide (rGO) were achieved via esterification between 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (HTEMPO) and a high concentration of carboxylated rGO. The fold on the surface of rGO shortens the distance of electron transport between radical monomers, thereby enhancing the conductivity of NO-g-rGO, which showed a high specific capacity of 256 mA h g⁻¹ after 200 cycles. The dramatic performance of NO-g-rGO was achieved through promoting the conductivity of NO. As a novel concept, this work provides a fresh perspective on the application of organic radical cathodes in high energy density LIBs.

The accuracy of Peukert’s battery capacity equation may decrease under the conditions of variable current and variable temperatures. Some researchers have previously tried to overcome the lack of C-rate change. However, the dependence of battery capacity on temperature is still not included. In this paper, we mainly studied the capacity reduction effect of batteries under variable temperatures. The proposed method can calculate the battery’s available capacity according to the specific discharge conditions. The experimental method proposed in this paper provides a reasonable test method to generate the required coefficients in order to establish a state of charge prediction model with high accuracy. After establishing the method, we can make a real-time prediction of the available energy of battery including the remaining energy of battery. From the result, we can see that the result is of great precision and the method is valuable.

In this paper, the battery inconsistency equalisation strategy is investigated and a novel fusion model based on equivalent circuit models is proposed. The three equivalent circuit models, 1RC, 2RC and PNGV, are weighted and fused by BP neuron network, which realizes the complementary advantages of the three equivalent circuit models. Even though the estimated values of all three models are lower than the true value, they can still be close to the true value after reasonable weight allocation. With reference to the open-source DST dynamic operating test data from the Advanced Battery Association of America, a comparison is made with the three common equivalent circuit models of 1RC, 2RC and PNGV. It is found that the proposed novel fusion model has the highest estimation accuracy with a maximum error of only 0.00947; the RMSE is 0.00217. The 1RC equivalent circuit model has the worst accuracy with a maximum error of 0.10145 and an RMSE of 0.02153. The 2RC and PNGV models have accuracies between the two. Then an active equalisation system is constructed to realise the charge equalisation of multiple unbalanced single batteries by distributed power supply. The PSO-PID strategy is used to control the topology circuit for adaptive equalisation. The equalisation effect of different sized battery packs is verified by simulation. Compared with the traditional logic control strategy, the method is simple and effective, and the equalisation effect is better as the number of inconsistent battery cells increases. In a battery pack with five initial SOC inconsistencies, the inter-cell variability is quickly equalised. When dynamic disturbances are introduced into the system, the algorithm also keeps the battery packs within the equalisation range with an average variance of 0.0016.

There has been a great deal of research in recent years to develop advanced water electrolysis systems for energy-saving hydrogen production. Herein, a hybrid saline-base electrolysis (SBE) system was fabricated that is a combination of traditional alkaline water splitting and a direct saline/seawater electrolysis system. In this system, it was demonstrated that nickel sulfide-based catalysts were stable and highly active for the saline hydrogen evolution reaction and alkaline oxygen evolution reaction (OER). Based on the large difference in the thermodynamics and kinetics between the saline OER and alkaline OER, the SBE system only needed a voltage of 1.55 V to attain 10 mA cm⁻², which is 120 and at least 375 mV lower than those for the alkaline and saline electrolysis systems, respectively. This system also exhibits high durability for hydrogen production whether at a low or high current. Moreover, it was also proven that the urea-assisted SBE system with further reduced cell voltage and the natural seawater-base hybrid electrolysis system were feasible.