Carbon dioxide and light are two major prerequisites of photosynthesis. Rising CO2 levels in oceanic surface waters in combination with ample light supply are therefore often considered stimulatory to marine primary production(1-3). Here we show that the combination of an increase in both CO2 and light exposure negatively impacts photosynthesis and growth of marine primary producers. When exposed to CO2 concentrations projected for the end of this century(4), natural phytoplankton assemblages of the South China Sea responded with decreased primary production and increased light stress at light intensities representative of the upper surface layer. The phytoplankton community shifted away from diatoms, the dominant phytoplankton group during our field campaigns. To examine the underlying mechanisms of the observed responses, we grew diatoms at different CO2 concentrations and under varying levels (5-100%) of solar radiation experienced by the phytoplankton at different depths of the euphotic zone. Above 22-36% of incident surface irradiance, growth rates in the high-CO2-grown cells were inversely related to light levels and exhibited reduced thresholds at which light becomes inhibitory. Future shoaling of upper-mixed-layer depths will expose phytoplankton to increased mean light intensities(5). In combination with rising CO2 levels, this may cause a widespread decline in marine primary production and a community shift away from diatoms, the main algal group that supports higher trophic levels and carbon export in the ocean.National Basic Research Program of China [2009CB421207, 2011CB200902]; National Natural Science Foundation of China [41120164007, 40930846]; Changjiang Scholars and Innovative Research Team project [IRT0941]; Ministry of Science and Technology [S2012GR0290]; United States National Science Foundation Division of Ocean Sciences [0942379, 0962309, 1043748]; German Ministry of Education and Research; 111 project; State Key Laboratory of Marine Environmental Science (Xiamen University); German Academic Exchange Service (DAAD

It is still a big challenge to stabilize a Ni-rich cathode interface at high current rate and a long-term cycle in the present Li-ion battery for electric vehicles. In this work, N,O-bis(trimethylsilyl)acetamide (BSA) is utilized as a multifunctional electrolyte additive to stabilize the LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode interface and enhance its electrochemical performance. After 200 cycles, the LiNi 0.8 Co 0.1 Mn 0.1 O 2 /Li cell at 1C rate with 0.5% BSA shows improved capacity retention of 86%, while it shows only 69.4% with the baseline electrolyte. When the discharge rate is increased to 2C, the LiNi 0.8 Co 0.1 Mn 0.1 O 2 /Li cell with BSA additive shows improved capacity retention of 72.6% after 400 cycles, while the counterpart is only 49.5%. The experimental results show that HF and H 2 O can be scavenged by BSA, and the hydrolysis of LiPF 6 is reduced. Moreover, the BSA additive can be preferentially oxidized during the charging process and form a robust, uniform electrode/electrolyte interface film on the NCM811 cathode surface. Consequently, a better CEI film can suppress the electrolyte decomposition, improve cathode interface stability, and alleviate transition metal ions dissolution.

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In this work, we investigate the effects of three different sulfur-containing additives, particularly ethylene sulfate (or 1,3,2dioxathiolane-2,2-dioxide (DTD)), 1,3-propane sultone (1,3-PS) and ethylene sulfite (ES) on the cycling and high temperature storage performance of high-voltage LiCoO 2 and artificial graphite electrodes. These additives process the different sulfur-containing functional groups and exhibit different performance, so that the impacts of changes to the functional group on the electrochemical behavior are interesting to study. Our aim is to understand the relationships between functional groups of these kinds of additives and their roles in improvement of the electrochemical and storage performance of the electrodes. The results clearly indicate that three additives are involved in film-formation on the surface of LiCoO 2 and graphite. Among them, CEI (cathode electrolyte interphase) films formed by DTD and 1,3-PS covered on cathode are thin and stable, thus they can cause a significant improvement of cycle performance in high voltage LiCoO 2 . Also, the SEI film happened in anode of graphite formed by DTD can deliver a good performance at low temperature. On the contrary, the CEI or solid electrolyte interphase (SEI) films formed by ES are not dense and unstable. Therefore it is detrimental to the cycle performance at room, low and elevated temperature.