Short-Process Regeneration of Highly Stable Spherical LiCoO2 Cathode Materials from Spent Lithium-Ion Batteries through Carbonate Precipitation.

High-efficacy recycling of spent lithium cobalt oxide (LiCoO2 ) batteries is one of the key tasks in realizing a global resource security strategy due to the rareness of lithium (Li) and cobalt (Co) resources. However, it is of great significance to develop the innovative recycle methods for spent LiCoO2 , simultaneously realizing the efficient recovery of valuable elements and the regeneration of high-performance LiCoO2 . Herein, a novel strategy of regenerating LiCoO2 cathode is proposed, which involves the preparation of micro-spherical aluminum (Al)-doped lithium-lacked precursor (Li2x Co1-x-y Al2/3y CO3, remarked as "PLCAC") via ammonium bicarbonate coprecipitation. The comprehensive conditions affecting particle growth kinetics, morphology and particle size the has been investigated in detail by physical characterizations and electrochemical measurements. And the optimized Al-doped LiCoO2 materials with high-density sphericity (LiCo1-z Alz O2 , remarked as "LCAO") shows a high initial specific capacity of 161 mAh g-1 at 0.1 C and excellent capacity retention of 99.5 % within 100 cycles at 1 C in the voltage range of 2.8 to 4.3 V. Our work provides valuable insights into the featured design of LiCoO2 precursors and cathode materials from spent LiCoO2 batteries, potentially guaranteeing the high-efficacy recycling and utilization of strategic resources.

Fast and Precise Temperature Control for Axon Stretch Growth Bioreactor Based on Fuzzy PID Control.

A suitable environment is essential for successful long-term cell culturing in vitro. Too high or too low temperature will affect the growth of cells, so we need to maintain the constant temperature of the cell culture environment. Usually, cells are cultured in a cell incubator, and the constant temperature is provided by the cell incubator. Recently, we have developed a multi-channel axon stretch growth bioreactor for rapid acquisition of autologous nerve tissue. Since the motor and controller are placed in the incubator for a long time, the service life of the equipment will be shortened or even damaged due to high humidity and weak acid environment. In order to enable the axon stretch growth bioreactor to culture cells independently, we designed a constant temperature control system for the device. Firstly, the simulation results show that the fuzzy PID control reduces the overshoot and improves the traditional PID control with large overshoot and low control precision. Then, the two control algorithms were applied to the multi-channel axon stretch growth bioreactor by STM32F4 microcontroller. The experimental data show that the fuzzy PID control algorithm has good control effect and can meet the requirement of constant temperature of cell growth. Finally, nerve cells derived from human pluripotent stem cells were successfully cultured in a cell culture amplification chamber under a constant temperature environment provided by a fuzzy PID controller, and well-developed axons could be seen. In the future, we may transplant stretch growth axons into living organisms to repair nerve damage.