Thermal safety boundary of lithium-ion battery at different state of charge

Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charges(SOCs)has significant implications for reinforcing the thermal safety design of the lithium-ion battery module.This study first investigates the thermal safety boundary(TSB)correspondence at the cells and modules level under the guidance of a newly proposed concept,safe electric quantity boundary(SEQB).A reasonable thermal runaway propagation(TRP)judgment indicator,peak heat transfer power(PHTP),is proposed to predict whether TRP occurs.Moreover,a validated 3D model is used to quantitatively clarify the TSB at different SOCs from the perspective of PHTP,TR trigger temperature,SOC,and the full cycle life.Besides,three different TRP transfer modes are discovered.The interconversion relationship of three different TRP modes is investigated from the perspective of PHTP.This paper explores the TSB of LIBs under different SOCs at both cell and module levels for the first time,which has great significance in guiding the thermal safety design of battery systems.

S-enriched porous polymer derived N-doped porous carbons for electrochemical energy storage and conversion

Porous polymers have been recently recog- nized as one of the most important precursors for fabrication of heteroatom-doped porous carbons due to the intrinsic porous structure, easy available heteroatom- containing monomers and versatile polymerization meth- ods. However, the heteroatom elements in as-produced porous carbons are quite relied on monomers. So far, the manipulating of heteroatom in porous polymer derived porous carbons are still very rare and challenge. In this work, a sulfur-enriched porous polymer, which was prepared from a diacetylene-linked porous polymer, was used as precursor to prepare S-doped and/or N-doped porous carbons under nitrogen and/or ammonia atmo- spheres. Remarkably, S content can sharply decrease from 36.3% to 0.05% after ammonia treatment. The N content and specific surface area of as-fabricated porous carbons can reach up to 1.32% and 1508 m^2·g^-1, respectively. As the electrode materials for electrical double-layer capacitors, as-fabricated porous carbons exhibit high specific capacitance of up to 431.6 F·g^-1 at 5 mW·s^-1 and excellent cycling stability of 99.74% capacitance retention after 3000 cycles at 100 mV·s^-1. Furthermore, as the electro- chemical catalysts for oxygen reduction reaction, as- fabricated porous carbons presented ultralow half-wave- potential of 0.78 V versus RHE. This work not only offers a new strategy for manipulating S and N doping features for the porous carbons derived from S-containing porous polymers, but also paves the way for the structure- performance interrelationship study of heteroatoms co- doped porous carbon for energy applications.

Impact of living donor liver with steatosis and idiopathic portal inflammation on clinical outcomes in pediatric liver transplantation:Beijing experience

Background:To evaluate the impact of steatosis and/or idiopathic portal inflammation(IPI)in living donor livers on recipients’clinical outcomes.Methods:We assessed 305 qualified donor liver samples from June 2013 to December 2018.Donors and recipients’clinical characteristics,including follow-up data were retrieved.The graft and overall survival with/without steatosis or portal inflammation were compared by Kaplan-Meier analysis.Results:For living donors,the medium age of was 31.2(28,35.8)years old;liver histopathology showed macrovesicular steatosis:0-5%264/305(86.6%)and 5-30%41/305(13.4%),IPI:no 220/305(72.1%)and mild 85/305(27.9%).For recipients,the medium age was 1.0(0.6,1.5)years old;the median pediatric-end-stage-liver-disease score was 16(5.0,26.0)and medium follow-up time was 32.8(24.8,52.0)months.Biliary atresia(69.5%)was the main indication for liver transplantation(LT).Conclusions:The presence of steatosis and portal inflammation of the donor liver did not impact the clinical outcomes including transaminase or bilirubin normalization,short-/long-term complications and recipients’survival.However,recipients with high pediatric-end-stage-liver-disease score(>16)receiving donor liver with portal inflammation,but not steatosis,had trend negative effect on recipients’survival.In conclusion,donor livers with mild steatosis and portal inflammation were qualified for pediatric living donor LT.However,donor liver with mild portal inflammation would better not be allocated to recipients with high pediatric-end-stage-liver-disease score.This study provided new evidence in pediatric living donor liver allocation.