The state-of-health (SOH) of lithium-ion batteries (LIBs) is a key parameter that characterizes their real lifespan. To improve the accuracy of SOH estimation for LIBs, a novel SOH estimation method based on health factors and improved long short-term memory (LSTM) neural network is proposed. First, ten health factors that are highly correlated with the changes in SOH are selected as the characteristics of SOH. Second, the particle swarm optimization (PSO) algorithm is introduced to optimize the hyper-parameter of the LSTM neural network, and an estimation model based on PSO-LSTM is constructed. Finally, the extracted health factors are used as model input to achieve an accurate estimation of SOH. Results show that when 70%, 60% and 50% of data from the whole sample are taken as the training set respectively and the remaining data is taken as the test set, the SOH estimation errors are mainly distributed in a range of less than 2%. Meanwhile, the PSO-LSTM model demonstrates higher estimation accuracy and better robustness compared with the existing LSTM and feed-forward neural networks (FNN).
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |