Electron spin resonance (ESR), magnetic susceptibility, and transport measurements were recently performed on a set of heat-treated polyparaphenylene (PPP)-based carbon samples, which are of significant interest as novel carbon-based anode electrodes in Li-ion batteries. Attention is focused on the evolution of the carbonaceous structures formed at low heat-treatment temperatures (T_(HT)) in the regime of 600 deg C <=T_(HT) <= 800 deg C, where percolative transport behavior isobserved. At the percolation threshold, T_(TH)~c approx approx 700 deg C the coexistence of two spin centers with peak-to-peak Lorentzian linewidths of DELTA H_(PP)(300K) chemical bounds 0.5 and 5.0 G is observed. The relatively high ratio of hydrogen:carbon (H/C) near T_(HT)~c is believed to influence the ESR results through an unresolved hyperfine interaction. Curie-Weiss temperatures are found from measurements of [I_(PP)( DELTA )~2]~(-1), where I_(PP) is the peak-to-peak lineheight, yielding results that are in agreement with static susceptibility, x(T), measurements. At low T_(HT), PPP-based materials exhibit a large amount of disorder and this is evidenced by the high density o f localized spins, N_C, which is obtained from a Curie-Weiss fit to X(T), assuming a spin quantum number of S chemical gounds 1/2. A odel explaining the microstructure and high electrochemical doping capacity of PPP samples heat-treated to 700 deg C can be related to Li-ion battery performance.
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机译：最近对一组热处理的聚萘基（PPP）的碳样品进行了电子旋转共振（ESR），磁化率和传输测量，这对于锂离子电池中的新型碳基阳极电极具有显着兴趣。注意力集中在600℃的低热处理温度（T_（HT））中形成的碳质结构的演变（T_（HT）<=（HT）<= 800℃，其中渗透到渗透行为。在渗透阈值下，T_（Th）〜C约约700℃，观察到具有达到峰值Lorentzian线宽的两种旋转中心的共存ΔH_（PP）（300K）化学界限0.5和5.0g。氢的相对高比率：据信近T_（HT）〜C接近T_（H / C），以通过未解析的高浓度相互作用影响ESR结果。从测量的[i_（pp）（delta）〜2]〜（-1）的测量中发现了Curie-weiss温度，其中I_（PP）是峰 - 峰的线路，产生与静态易感性一致的结果， x（t），测量。在低T_（HT）下，基于PPP的材料表现出大量的病症，这是通过旋转量子的柔软纺丝件获得的局部旋转的高密度N_C，这证明了这一点。 S Chemical Gounds 1/2的数量。解释PPP样品的微观结构和高电化学掺杂能力的静脉可以与锂离子电池性能有关。
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